EpidemiologyBiostatistics Exam Exam 2, 2001 PRINT YOUR LEGAL NAME:


 Bruno Jenkins
 1 years ago
 Views:
Transcription
1 EpidemiologyBiostatistics Exam Exam 2, 2001 PRINT YOUR LEGAL NAME: Instructions: This exam is 30% of your course grade. The maximum number of points for the course is 1,000; hence this exam is worth 300 points. There are 25 questions on this exam. Each question is worth 12 points to yield the maximum total of 300 points for this exam. For questions 1 12, record the best answer in pencil on the answer sheet provided. For questions 13 25, write your answers in the spaces provided. Submit the exam and your answer sheet as directed after you have completed the exam. Be sure that you have printed your legal name on the top of each page. 1. A parent calls the local Department of Public Health concerned that several children in his small community have been diagnosed with myocarditis, an inflammation of the heart muscle. After recording the information, one of the very first things the public health official should do is: (Select the best answer.) a. Gather information from sources in the small community to determine if there is a greater than expected number of cases of myocarditis. b. Conduct active surveillance by capturing ticks from area woods to determine the prevalence of the bacteria that causes Lyme Disease. c. Conduct a case control study to determine if cases were more likely than controls to have eaten in the nearby fastfood restaurant. d. Conduct a prospective cohort study to determine if exposure to wooded areas is associated with the development of myocarditis. e. In the interest of public safety, immediately inform the media that there may be an epidemic of a potentially serious disease. 2. Height is normally distributed in Town A. Researchers randomly select 50 subjects from Town A and calculate their mean height and its 95% confidence interval to make an inference about the true average height in Town A. Select the best statement: a. Confounding could lead to an erroneous conclusion about Town A s true average height. b. The sample size of 50 is too small to calculate a 95% confidence interval on the mean. c. If the researchers had drawn a sample size of 100 rather than 50, the 95% confidence interval around the mean would be more narrow. d. It is not appropriate to use a 95% confidence interval on the sample mean to make an inference about the true mean of Town A. e. Interviewer bias could lead to an erroneous conclusion about Town A s true average height.
2 PRINT YOUR LEGAL NAME: 3. Multiple linear regression analysis (multivariate analysis) can be used to: (Select the best statement.) a. adjust for confounding by adding the confounding variable as an independent variable. b. determine if a study result is clinically important. c. adjust for loss to followup bias. d. calculate a study s power. e. correct the pvalue for multiple comparisons. 4. The standard error of the mean is: (Select the best statement.) a. used to calculate the mean of the sample. b. used whenever the researcher wants to adjust for confounding by the direct or indirect standardization method. c. the sample size divided by the square root of the sample standard deviation. d. a type of sampling bias that can lead to an erroneous study conclusion. e. the standard deviation of the distribution of sample means. 5. Researchers want to make an inference about the average serum (blood) cholesterol levels of students in college B. They will do this by randomly sampling 500 students from college B. The researchers want to be absolutely certain that they sample 250 male students and 250 female students. The researchers should: (Select the best statement.) a. calculate a 50% confidence interval on the sample mean. b. use the methods of stratified sampling. c. conduct a randomized controlled trial to help assure comparability of men and women. d. randomly select 500 subjects, and if there are 252 men and 248 women, discard the men with the highest two serum cholesterol levels and handselect two female students. e. perform a stratified ttest on the average serum cholesterol levels of the males vs. the females.
3 PRINT YOUR LEGAL NAME: 6. Researchers prospectively follow a group of 100 vegetarians and 200 nonvegetarians. After 30 years, 8 of the vegetarians develop heart disease and 20 of the nonvegetarians develop heart disease. The 95% confidence interval on the relative risk of 0.8 extends from 0.6 to 0.9. Alpha was set at Select the best statement: a. Vegetarians were 80% less likely to develop heart disease over 30 years vs. the nonvegetarians. b. The relative risk of 0.8 is not statistically significant as the 95% confidence interval contains the value 0.8. c. Vegetarians were 20% less likely to develop heart disease over 30 years vs. nonvegetarians. d. The study had 95% power to detect a true difference of 20% or more. e. The researchers should have calculated an odds ratio rather than a relative risk. 7. The grades on exam C are normally distributed with a population mean of 75% and a population standard deviation of 5%. Select the best statement: a. The 95% confidence interval on the exam C distribution extends from 65% to 85%. b. 34% of the grades on exam C are between 75% and 80%. c. 65% of the grades on exam C are between 65% and 85%. d. The area under the entire curve of exam C grades could be less than 100%. e. 95% of the grades on exam C are between 75% and 85%. 8. Researchers want to determine if the proportion of men from town A who smoke cigarettes is different than the proportion of women from town A who smoke cigarettes. The researchers randomly select 1,000 men and 1,200 women from town A and they ask them if they smoke cigarettes. Subjects are only permitted to answer yes or no to the question. Select the best statement: a. Smoking could be a confounder in this study. b. Gender could be a confounder in this study. c. The study likely has poor internal validity as there are more women in the study than men. d. The researchers should test their hypothesis with a twosample ttest. e. The researchers should test their hypothesis with a chisquare test.
4 PRINT YOUR LEGAL NAME: 9. Researchers develop a simple regression model with diastolic blood pressure as the dependent variable and height as the independent variable. They determine that R squared is 68%. Select the best statement: a. 68% of the variability in diastolic blood pressure is accounted for by height. b. 68% of the variability in height is accounted for by diastolic blood pressure. c. One standard deviation below and above R squared contains 68% of the heights. d. The R squared is at the 68 th percentile of the distribution of diastolic blood pressures. e. As diastolic blood pressure is a continuous variable, the researchers should use a logistic regression model. 10. Select the best statement concerning Pearson s correlation coefficient: a. It is an approximation of the mean of two variables. b. It reflects the magnitude of the association for linear and nonlinear relationships between two continuous variables. c. A Pearson s correlation coefficient of zero indicates there is no linear association between the two variables. d. A Pearson s correlation coefficient of positive one indicates there is no linear association between the two variables. e. A Pearson s correlation coefficient of negative one indicates there is a nonlinear relationship between the two variables. 11. Researchers conduct a randomized controlled trial comparing subjects on Med A vs. Med B in the prevention of strokes. They determine that 200 subjects, 100 subjects in each arm, are required to have a power of 90% to detect a true difference of 5% or more. One percent of the subjects on Med A developed a stroke while 4% of the subjects on Med B developed a stroke. Alpha was set at 0.05 and the resulting Pvalue was Select the best statement: a. The researchers should reject the null hypothesis. b. Given the null hypothesis is correct, the probability of obtaining a difference of 5% or more due to chance alone is 7%. c. Given the alternative hypothesis is correct, the probability of obtaining a difference of 5% or more due to chance alone is 7%. d. Given the null hypothesis is correct, the probability of obtaining a difference of 3% or more due to chance alone is 90%. e. Given the null hypothesis is correct, the probability of obtaining a difference of 3% or more due to chance alone is 7%.
5 PRINT YOUR LEGAL NAME: 12. Referring to question 11 above: (Select the best statement.) a. The probability that a Type II Error occurred is 7%. b. The study might have insufficient power to detect a true difference of 3% or more. c. The probability that a Type II Error occurred is 3%. d. The researchers should reject the null hypothesis. e. The probability that a Type I Error occurred is 3%. FOR QUESTIONS 13 25, WRITE THE ANSWERS IN THE SPACES PROVIDED. 13. When is it appropriate to use a nonparametric test for continuous data? 14. Researchers develop the following regression equation: Diastolic Blood Pressure in mm Hg = constant + (slope) (age in years) If the slope is 0.50, how will each additional year of age affect the diastolic blood pressure? 15. Under what circumstances might a researcher decide to transform continuous data?
6 PRINT YOUR LEGAL NAME: 16. What is the difference between a statistic and a parameter? 17. A researcher records the serum (blood) HDL level from 100 randomly selected subjects from town A. The researcher then places the 100 subjects on med A, an experimental medicine to lower serum HDL, for six months and again records the serum HDL levels of the 100 subjects. Assume the serum HDL levels are normally distributed. What statistical test should the researcher use to determine if med A lowered the HDL levels in the subjects? 18. The prevalence of Disease X is known to be 10% in town A. The sensitivity of a test for Disease X is 90% and the specificity of a test for Disease X is 70%. Calculate the predictive value negative of a test for Disease X in town A. Show your work. 19. A researcher conducts a randomized controlled trial for subjects assigned to med A vs. med B in the prevention of heart disease. Because the researcher intends to perform multiple outcome comparisons, alpha is set at The researcher determined that a minimum of 100 subjects would be necessary to have a power of 80% to detect a true difference of 3% or more. The researcher reports that 10% of the subjects on med A developed heart disease while 15% of the subjects on med B developed heart disease with a resulting Pvalue of What should the researcher s decision be regarding the null hypothesis? Explain your answer.
7 PRINT YOUR LEGAL NAME: 20. Referring to question # 19 above, write a complete sentence interpreting the P value and containing the appropriate data from the results. It is not acceptable to simply state that the Pvalue is or is not statistically significant. 21. Two hospitals choose to compare their CABG mortality rates over a oneyear period. The hospitals have agreed to look at the mortality data considering patients with or without a diagnosis of hypertension (high blood pressure) at the time of the operation. The data for Hospital A are shown in the following table: Hospital A CABG Number Deaths Hypertension Diagnosis No Hypertension Diagnosis The data for Hospital B are shown in the following table: Hospital B CABG Number Deaths Hypertension Diagnosis No Hypertension Diagnosis The hospital officials report that the CABG mortality rates are the same between the two hospitals. Using the data from these tables only, was the diagnosis of hypertension a confounder in the comparison between Hospital A and Hospital B such that an adjustment would be required? Explain your answer.
8 PRINT YOUR LGAL NAME: 22. Researchers want to determine if there is a difference in the average height between Tufts medical students and Harvard medical students. They randomly select 100 students from each school. The heights are normally distributed in each group. What statistical test should the researchers use to test the hypothesis? 23. There are pros and cons to the various types of epidemiology studies. List one pro and one con of a randomized controlled trial. (Do not list more than one pro and one con.) 24. The scores on an exam are normally distributed with a population mean of 80% and a population standard deviation of 5%. A student scores 75% on the exam. What percent of the exam scores were higher than the student s exam score? Show your work. 25. Researchers want to make an inference about the average systolic blood pressure of Tufts medical students. The researchers report that the systolic blood pressures are normally distributed. They randomly select 100 students and report that the sample mean is 120 mm Hg with a 95% confidence interval extending from 115 mm Hg to 125 mm Hg. Write a sentence interpreting this confidence interval. END OF EXAM
p1^ = 0.18 p2^ = 0.12 A) 0.150 B) 0.387 C) 0.300 D) 0.188 3) n 1 = 570 n 2 = 1992 x 1 = 143 x 2 = 550 A) 0.270 B) 0.541 C) 0.520 D) 0.
Practice for chapter 9 and 10 Disclaimer: the actual exam does not mirror this. This is meant for practicing questions only. The actual exam in not multiple choice. Find the number of successes x suggested
More informationC. The null hypothesis is not rejected when the alternative hypothesis is true. A. population parameters.
Sample Multiple Choice Questions for the material since Midterm 2. Sample questions from Midterms and 2 are also representative of questions that may appear on the final exam.. A randomly selected sample
More informationEBM Cheat Sheet Measurements Card
EBM Cheat Sheet Measurements Card Basic terms: Prevalence = Number of existing cases of disease at a point in time / Total population. Notes: Numerator includes old and new cases Prevalence is crosssectional
More informationBivariate Analysis. Correlation. Correlation. Pearson's Correlation Coefficient. Variable 1. Variable 2
Bivariate Analysis Variable 2 LEVELS >2 LEVELS COTIUOUS Correlation Used when you measure two continuous variables. Variable 2 2 LEVELS X 2 >2 LEVELS X 2 COTIUOUS ttest X 2 X 2 AOVA (Ftest) ttest AOVA
More informationOutline of Topics. Statistical Methods I. Types of Data. Descriptive Statistics
Statistical Methods I Tamekia L. Jones, Ph.D. (tjones@cog.ufl.edu) Research Assistant Professor Children s Oncology Group Statistics & Data Center Department of Biostatistics Colleges of Medicine and Public
More informationII. DISTRIBUTIONS distribution normal distribution. standard scores
Appendix D Basic Measurement And Statistics The following information was developed by Steven Rothke, PhD, Department of Psychology, Rehabilitation Institute of Chicago (RIC) and expanded by Mary F. Schmidt,
More informationInferential Statistics
Inferential Statistics Sampling and the normal distribution Zscores Confidence levels and intervals Hypothesis testing Commonly used statistical methods Inferential Statistics Descriptive statistics are
More informationSTATISTICS 8 CHAPTERS 1 TO 6, SAMPLE MULTIPLE CHOICE QUESTIONS
STATISTICS 8 CHAPTERS 1 TO 6, SAMPLE MULTIPLE CHOICE QUESTIONS Correct answers are in bold italics.. This scenario applies to Questions 1 and 2: A study was done to compare the lung capacity of coal miners
More informationCohort Studies. Sukon Kanchanaraksa, PhD Johns Hopkins University
This work is licensed under a Creative Commons AttributionNonCommercialShareAlike License. Your use of this material constitutes acceptance of that license and the conditions of use of materials on this
More informationVariables and Data A variable contains data about anything we measure. For example; age or gender of the participants or their score on a test.
The Analysis of Research Data The design of any project will determine what sort of statistical tests you should perform on your data and how successful the data analysis will be. For example if you decide
More informationBiostatistics: Types of Data Analysis
Biostatistics: Types of Data Analysis Theresa A Scott, MS Vanderbilt University Department of Biostatistics theresa.scott@vanderbilt.edu http://biostat.mc.vanderbilt.edu/theresascott Theresa A Scott, MS
More informationUnit 31 A Hypothesis Test about Correlation and Slope in a Simple Linear Regression
Unit 31 A Hypothesis Test about Correlation and Slope in a Simple Linear Regression Objectives: To perform a hypothesis test concerning the slope of a least squares line To recognize that testing for a
More informationBasic research methods. Basic research methods. Question: BRM.2. Question: BRM.1
BRM.1 The proportion of individuals with a particular disease who die from that condition is called... BRM.2 This study design examines factors that may contribute to a condition by comparing subjects
More informationDescriptive Statistics
Descriptive Statistics Primer Descriptive statistics Central tendency Variation Relative position Relationships Calculating descriptive statistics Descriptive Statistics Purpose to describe or summarize
More informationPRACTICE PROBLEMS FOR BIOSTATISTICS
PRACTICE PROBLEMS FOR BIOSTATISTICS BIOSTATISTICS DESCRIBING DATA, THE NORMAL DISTRIBUTION 1. The duration of time from first exposure to HIV infection to AIDS diagnosis is called the incubation period.
More informationAn Introduction to Statistics Course (ECOE 1302) Spring Semester 2011 Chapter 10 TWOSAMPLE TESTS
The Islamic University of Gaza Faculty of Commerce Department of Economics and Political Sciences An Introduction to Statistics Course (ECOE 130) Spring Semester 011 Chapter 10 TWOSAMPLE TESTS Practice
More informationBA 275 Review Problems  Week 5 (10/23/0610/27/06) CD Lessons: 48, 49, 50, 51, 52 Textbook: pp. 380394
BA 275 Review Problems  Week 5 (10/23/0610/27/06) CD Lessons: 48, 49, 50, 51, 52 Textbook: pp. 380394 1. Does vigorous exercise affect concentration? In general, the time needed for people to complete
More informationConstruct a scatterplot for the given data. 2) x Answer:
Review for Test 5 STA 2023 spr 2014 Name Given the linear correlation coefficient r and the sample size n, determine the critical values of r and use your finding to state whether or not the given r represents
More informationSample Exam #1 Elementary Statistics
Sample Exam #1 Elementary Statistics Instructions. No books, notes, or calculators are allowed. 1. Some variables that were recorded while studying diets of sharks are given below. Which of the variables
More informationMULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
Open book and note Calculator OK Multiple Choice 1 point each MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Find the mean for the given sample data.
More informationGuide to Biostatistics
MedPage Tools Guide to Biostatistics Study Designs Here is a compilation of important epidemiologic and common biostatistical terms used in medical research. You can use it as a reference guide when reading
More informationGeneral Method: Difference of Means. 3. Calculate df: either WelchSatterthwaite formula or simpler df = min(n 1, n 2 ) 1.
General Method: Difference of Means 1. Calculate x 1, x 2, SE 1, SE 2. 2. Combined SE = SE1 2 + SE2 2. ASSUMES INDEPENDENT SAMPLES. 3. Calculate df: either WelchSatterthwaite formula or simpler df = min(n
More informationChapter 7: Simple linear regression Learning Objectives
Chapter 7: Simple linear regression Learning Objectives Reading: Section 7.1 of OpenIntro Statistics Video: Correlation vs. causation, YouTube (2:19) Video: Intro to Linear Regression, YouTube (5:18) 
More information11. Analysis of Casecontrol Studies Logistic Regression
Research methods II 113 11. Analysis of Casecontrol Studies Logistic Regression This chapter builds upon and further develops the concepts and strategies described in Ch.6 of Mother and Child Health:
More informationIntroduction to Statistics and Quantitative Research Methods
Introduction to Statistics and Quantitative Research Methods Purpose of Presentation To aid in the understanding of basic statistics, including terminology, common terms, and common statistical methods.
More informationStudy Guide for the Final Exam
Study Guide for the Final Exam When studying, remember that the computational portion of the exam will only involve new material (covered after the second midterm), that material from Exam 1 will make
More informationFINAL EXAM REVIEW  Fa 13
FINAL EXAM REVIEW  Fa 13 Determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate. 1) The temperatures of eight different plastic spheres. 2) The sample
More informationChapter Five: Paired Samples Methods 1/38
Chapter Five: Paired Samples Methods 1/38 5.1 Introduction 2/38 Introduction Paired data arise with some frequency in a variety of research contexts. Patients might have a particular type of laser surgery
More informationSAMPLING & INFERENTIAL STATISTICS. Sampling is necessary to make inferences about a population.
SAMPLING & INFERENTIAL STATISTICS Sampling is necessary to make inferences about a population. SAMPLING The group that you observe or collect data from is the sample. The group that you make generalizations
More informationMortality Assessment Technology: A New Tool for Life Insurance Underwriting
Mortality Assessment Technology: A New Tool for Life Insurance Underwriting Guizhou Hu, MD, PhD BioSignia, Inc, Durham, North Carolina Abstract The ability to more accurately predict chronic disease morbidity
More informationOverview of NonParametric Statistics PRESENTER: ELAINE EISENBEISZ OWNER AND PRINCIPAL, OMEGA STATISTICS
Overview of NonParametric Statistics PRESENTER: ELAINE EISENBEISZ OWNER AND PRINCIPAL, OMEGA STATISTICS About Omega Statistics Private practice consultancy based in Southern California, Medical and Clinical
More informationGood luck! BUSINESS STATISTICS FINAL EXAM INSTRUCTIONS. Name:
Glo bal Leadership M BA BUSINESS STATISTICS FINAL EXAM Name: INSTRUCTIONS 1. Do not open this exam until instructed to do so. 2. Be sure to fill in your name before starting the exam. 3. You have two hours
More informationWHAT IS A JOURNAL CLUB?
WHAT IS A JOURNAL CLUB? With its September 2002 issue, the American Journal of Critical Care debuts a new feature, the AJCC Journal Club. Each issue of the journal will now feature an AJCC Journal Club
More informationExamination Orientation Practice Items
Examination Orientation Practice Items 1 Contents TEST QUESTION FORMATS... 3 A. MULTLPLE CHOICE FORMAT SINGLE ONE BEST ANSWER... 3 STRATEGIES FOR ANSWERING SINGLE ONE BEST ANSWER TEST QUESTIONS... 3 EXAMPLES
More informationSimple Sensitivity Analyses for Matched Samples. CRSP 500 Spring 2008 Thomas E. Love, Ph. D., Instructor. Goal of a Formal Sensitivity Analysis
Goal of a Formal Sensitivity Analysis To replace a general qualitative statement that applies in all observational studies the association we observe between treatment and outcome does not imply causation
More informationSTATISTICS 8, FINAL EXAM. Last six digits of Student ID#: Circle your Discussion Section: 1 2 3 4
STATISTICS 8, FINAL EXAM NAME: KEY Seat Number: Last six digits of Student ID#: Circle your Discussion Section: 1 2 3 4 Make sure you have 8 pages. You will be provided with a table as well, as a separate
More informationPrinciples of Hypothesis Testing for Public Health
Principles of Hypothesis Testing for Public Health Laura Lee Johnson, Ph.D. Statistician National Center for Complementary and Alternative Medicine johnslau@mail.nih.gov Fall 2011 Answers to Questions
More informationUCLA STAT 13 Statistical Methods  Final Exam Review Solutions Chapter 7 Sampling Distributions of Estimates
UCLA STAT 13 Statistical Methods  Final Exam Review Solutions Chapter 7 Sampling Distributions of Estimates 1. (a) (i) µ µ (ii) σ σ n is exactly Normally distributed. (c) (i) is approximately Normally
More information"Statistical methods are objective methods by which group trends are abstracted from observations on many separate individuals." 1
BASIC STATISTICAL THEORY / 3 CHAPTER ONE BASIC STATISTICAL THEORY "Statistical methods are objective methods by which group trends are abstracted from observations on many separate individuals." 1 Medicine
More informationIntroduction. Hypothesis Testing. Hypothesis Testing. Significance Testing
Introduction Hypothesis Testing Mark Lunt Arthritis Research UK Centre for Ecellence in Epidemiology University of Manchester 13/10/2015 We saw last week that we can never know the population parameters
More informationAP Statistics 2011 Scoring Guidelines
AP Statistics 2011 Scoring Guidelines The College Board The College Board is a notforprofit membership association whose mission is to connect students to college success and opportunity. Founded in
More informationStatistics 2014 Scoring Guidelines
AP Statistics 2014 Scoring Guidelines College Board, Advanced Placement Program, AP, AP Central, and the acorn logo are registered trademarks of the College Board. AP Central is the official online home
More informationStatistics for Sports Medicine
Statistics for Sports Medicine Suzanne Hecht, MD University of Minnesota (suzanne.hecht@gmail.com) Fellow s Research Conference July 2012: Philadelphia GOALS Try not to bore you to death!! Try to teach
More informationCORRELATIONAL ANALYSIS: PEARSON S r Purpose of correlational analysis The purpose of performing a correlational analysis: To discover whether there
CORRELATIONAL ANALYSIS: PEARSON S r Purpose of correlational analysis The purpose of performing a correlational analysis: To discover whether there is a relationship between variables, To find out the
More informationSydney Roberts Predicting Age Group Swimmers 50 Freestyle Time 1. 1. Introduction p. 2. 2. Statistical Methods Used p. 5. 3. 10 and under Males p.
Sydney Roberts Predicting Age Group Swimmers 50 Freestyle Time 1 Table of Contents 1. Introduction p. 2 2. Statistical Methods Used p. 5 3. 10 and under Males p. 8 4. 11 and up Males p. 10 5. 10 and under
More informationFactors affecting online sales
Factors affecting online sales Table of contents Summary... 1 Research questions... 1 The dataset... 2 Descriptive statistics: The exploratory stage... 3 Confidence intervals... 4 Hypothesis tests... 4
More informationX X X a) perfect linear correlation b) no correlation c) positive correlation (r = 1) (r = 0) (0 < r < 1)
CORRELATION AND REGRESSION / 47 CHAPTER EIGHT CORRELATION AND REGRESSION Correlation and regression are statistical methods that are commonly used in the medical literature to compare two or more variables.
More informationHYPOTHESIS TESTING (ONE SAMPLE)  CHAPTER 7 1. used confidence intervals to answer questions such as...
HYPOTHESIS TESTING (ONE SAMPLE)  CHAPTER 7 1 PREVIOUSLY used confidence intervals to answer questions such as... You know that 0.25% of women have red/green color blindness. You conduct a study of men
More informationRegression Analysis: A Complete Example
Regression Analysis: A Complete Example This section works out an example that includes all the topics we have discussed so far in this chapter. A complete example of regression analysis. PhotoDisc, Inc./Getty
More informationSTA201TE. 5. Measures of relationship: correlation (5%) Correlation coefficient; Pearson r; correlation and causation; proportion of common variance
Principles of Statistics STA201TE This TECEP is an introduction to descriptive and inferential statistics. Topics include: measures of central tendency, variability, correlation, regression, hypothesis
More informationData Analysis, Research Study Design and the IRB
Minding the pvalues p and Quartiles: Data Analysis, Research Study Design and the IRB Don AllensworthDavies, MSc Research Manager, Data Coordinating Center Boston University School of Public Health IRB
More informationSOLUTIONS TO BIOSTATISTICS PRACTICE PROBLEMS
SOLUTIONS TO BIOSTATISTICS PRACTICE PROBLEMS BIOSTATISTICS DESCRIBING DATA, THE NORMAL DISTRIBUTION SOLUTIONS 1. a. To calculate the mean, we just add up all 7 values, and divide by 7. In Xi i= 1 fancy
More informationIndependent t Test (Comparing Two Means)
Independent t Test (Comparing Two Means) The objectives of this lesson are to learn: the definition/purpose of independent ttest when to use the independent ttest the use of SPSS to complete an independent
More informationMULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. C) (a) 2 (b) 1
Unit 2 Review Name Use the given frequency distribution to find the (a) class width. (b) class midpoints of the first class. (c) class boundaries of the first class. 1) Miles (per day) 12 9 34 22 56
More informationStat 503. Solutions to Homework #11 (115 points) (11) (19)
Leucine (ng) Stat 503 Solutions to Homework #11 (115 points) Problem 1.3 (p. 536) In a study of protein synthesis in the oocyte (developing egg cell) of the frog Xenopus laevis, a biologist injected individual
More informationHYPOTHESIS TESTING (ONE SAMPLE)  CHAPTER 7 1. used confidence intervals to answer questions such as...
HYPOTHESIS TESTING (ONE SAMPLE)  CHAPTER 7 1 PREVIOUSLY used confidence intervals to answer questions such as... You know that 0.25% of women have red/green color blindness. You conduct a study of men
More informationRegression. Name: Class: Date: Multiple Choice Identify the choice that best completes the statement or answers the question.
Class: Date: Regression Multiple Choice Identify the choice that best completes the statement or answers the question. 1. Given the least squares regression line y8 = 5 2x: a. the relationship between
More informationLogistic regression: Model selection
Logistic regression: April 14 The WCGS data Measures of predictive power Today we will look at issues of model selection and measuring the predictive power of a model in logistic regression Our data set
More informationSimple Linear Regression Inference
Simple Linear Regression Inference 1 Inference requirements The Normality assumption of the stochastic term e is needed for inference even if it is not a OLS requirement. Therefore we have: Interpretation
More informationHypothesis testing S2
Basic medical statistics for clinical and experimental research Hypothesis testing S2 Katarzyna Jóźwiak k.jozwiak@nki.nl 2nd November 2015 1/43 Introduction Point estimation: use a sample statistic to
More informationUnit 26: Small Sample Inference for One Mean
Unit 26: Small Sample Inference for One Mean Prerequisites Students need the background on confidence intervals and significance tests covered in Units 24 and 25. Additional Topic Coverage Additional coverage
More informationResearch Variables. Measurement. Scales of Measurement. Chapter 4: Data & the Nature of Measurement
Chapter 4: Data & the Nature of Graziano, Raulin. Research Methods, a Process of Inquiry Presented by Dustin Adams Research Variables Variable Any characteristic that can take more than one form or value.
More informationHypothesis Testing for Two Variances
Hypothesis Testing for Two Variances The standard version of the twosample t test is used when the variances of the underlying populations are either known or assumed to be equal In other situations,
More informationNHS Diabetes Prevention Programme (NHS DPP) Nondiabetic hyperglycaemia. Produced by: National Cardiovascular Intelligence Network (NCVIN)
NHS Diabetes Prevention Programme (NHS DPP) Nondiabetic hyperglycaemia Produced by: National Cardiovascular Intelligence Network (NCVIN) Date: August 2015 About Public Health England Public Health England
More informationAP Statistics 2002 Scoring Guidelines
AP Statistics 2002 Scoring Guidelines The materials included in these files are intended for use by AP teachers for course and exam preparation in the classroom; permission for any other use must be sought
More informationAnalyzing Research Data Using Excel
Analyzing Research Data Using Excel Fraser Health Authority, 2012 The Fraser Health Authority ( FH ) authorizes the use, reproduction and/or modification of this publication for purposes other than commercial
More informationCHAPTER 13 SIMPLE LINEAR REGRESSION. Opening Example. Simple Regression. Linear Regression
Opening Example CHAPTER 13 SIMPLE LINEAR REGREION SIMPLE LINEAR REGREION! Simple Regression! Linear Regression Simple Regression Definition A regression model is a mathematical equation that descries the
More informationBusiness Statistics. Successful completion of Introductory and/or Intermediate Algebra courses is recommended before taking Business Statistics.
Business Course Text Bowerman, Bruce L., Richard T. O'Connell, J. B. Orris, and Dawn C. Porter. Essentials of Business, 2nd edition, McGrawHill/Irwin, 2008, ISBN: 9780073319889. Required Computing
More informationSample Size Estimation and Power Analysis
yumi Shintani, Ph.D., M.P.H. Sample Size Estimation and Power nalysis March 2008 yumi Shintani, PhD, MPH Department of Biostatistics Vanderbilt University 1 researcher conducted a study comparing the effect
More informationStatistics 100 Sample Final Questions (Note: These are mostly multiple choice, for extra practice. Your Final Exam will NOT have any multiple choice!
Statistics 100 Sample Final Questions (Note: These are mostly multiple choice, for extra practice. Your Final Exam will NOT have any multiple choice!) Part A  Multiple Choice Indicate the best choice
More informationNotes 8: Hypothesis Testing
Notes 8: Hypothesis Testing Julio Garín Department of Economics Statistics for Economics Spring 2012 (Stats for Econ) Hypothesis Testing Spring 2012 1 / 44 Introduction Why we conduct surveys? We want
More informationStatistics and research
Statistics and research Usaneya Perngparn Chitlada Areesantichai Drug Dependence Research Center (WHOCC for Research and Training in Drug Dependence) College of Public Health Sciences Chulolongkorn University,
More informationStudy Design and Statistical Analysis
Study Design and Statistical Analysis Anny H Xiang, PhD Department of Preventive Medicine University of Southern California Outline Designing Clinical Research Studies Statistical Data Analysis Designing
More informationInclusion and Exclusion Criteria
Inclusion and Exclusion Criteria Inclusion criteria = attributes of subjects that are essential for their selection to participate. Inclusion criteria function remove the influence of specific confounding
More informationLEVEL ONE MODULE EXAM PART ONE [Clinical Questions Literature Searching Types of Research Levels of Evidence Appraisal Scales Statistic Terminology]
1. What does the letter I correspond to in the PICO format? A. Interdisciplinary B. Interference C. Intersession D. Intervention 2. Which step of the evidencebased practice process incorporates clinical
More informationChapter 1112 1 Review
Chapter 1112 Review Name 1. In formulating hypotheses for a statistical test of significance, the null hypothesis is often a statement of no effect or no difference. the probability of observing the data
More informationPower and Sample Size. In epigenetic epidemiology studies
Power and Sample Size In epigenetic epidemiology studies Overview Pros and cons Working examples Concerns for epigenetic epidemiology Definition Power is the probability of detecting an effect, given that
More informationArticle. Heart health and cholesterol levels of Canadians, 2007 to 2009. Component of Statistics Canada Catalogue no. 82625X Health Fact Sheets
Component of Statistics Canada Catalogue no. 82625X Health Fact Sheets Article Heart health and cholesterol levels of Canadians, 2007 to 2009 March How to obtain more information For information about
More informationSample Size and Power in Clinical Trials
Sample Size and Power in Clinical Trials Version 1.0 May 011 1. Power of a Test. Factors affecting Power 3. Required Sample Size RELATED ISSUES 1. Effect Size. Test Statistics 3. Variation 4. Significance
More informationReasoning with Uncertainty More about Hypothesis Testing. Pvalues, types of errors, power of a test
Reasoning with Uncertainty More about Hypothesis Testing Pvalues, types of errors, power of a test PValues and Decisions Your conclusion about any null hypothesis should be accompanied by the Pvalue
More informationLesson 1: Comparison of Population Means Part c: Comparison of Two Means
Lesson : Comparison of Population Means Part c: Comparison of Two Means Welcome to lesson c. This third lesson of lesson will discuss hypothesis testing for two independent means. Steps in Hypothesis
More informationSection 14 Simple Linear Regression: Introduction to Least Squares Regression
Slide 1 Section 14 Simple Linear Regression: Introduction to Least Squares Regression There are several different measures of statistical association used for understanding the quantitative relationship
More informationChi Squared and Fisher's Exact Tests. Observed vs Expected Distributions
BMS 617 Statistical Techniques for the Biomedical Sciences Lecture 11: ChiSquared and Fisher's Exact Tests Chi Squared and Fisher's Exact Tests This lecture presents two similarly structured tests, Chisquared
More informationAP Statistics. Chapter 4 Review
Name AP Statistics Chapter 4 Review 1. In a study of the link between high blood pressure and cardiovascular disease, a group of white males aged 35 to 64 was followed for 5 years. At the beginning of
More informationAP Statistics 2012 Scoring Guidelines
AP Statistics 2012 Scoring Guidelines The College Board The College Board is a missiondriven notforprofit organization that connects students to college success and opportunity. Founded in 1900, the
More information3. There are three senior citizens in a room, ages 68, 70, and 72. If a seventyyearold person enters the room, the
TMTA Statistics Exam 2011 1. Last month, the mean and standard deviation of the paychecks of 10 employees of a small company were $1250 and $150, respectively. This month, each one of the 10 employees
More informationName: Date: Use the following to answer questions 34:
Name: Date: 1. Determine whether each of the following statements is true or false. A) The margin of error for a 95% confidence interval for the mean increases as the sample size increases. B) The margin
More information2 Precisionbased sample size calculations
Statistics: An introduction to sample size calculations Rosie Cornish. 2006. 1 Introduction One crucial aspect of study design is deciding how big your sample should be. If you increase your sample size
More informationDef: The standard normal distribution is a normal probability distribution that has a mean of 0 and a standard deviation of 1.
Lecture 6: Chapter 6: Normal Probability Distributions A normal distribution is a continuous probability distribution for a random variable x. The graph of a normal distribution is called the normal curve.
More informationSPSS Guide: Regression Analysis
SPSS Guide: Regression Analysis I put this together to give you a stepbystep guide for replicating what we did in the computer lab. It should help you run the tests we covered. The best way to get familiar
More informationTechnical Information
Technical Information Trials The questions for Progress Test in English (PTE) were developed by English subject experts at the National Foundation for Educational Research. For each test level of the paper
More informationModule 5 Hypotheses Tests: Comparing Two Groups
Module 5 Hypotheses Tests: Comparing Two Groups Objective: In medical research, we often compare the outcomes between two groups of patients, namely exposed and unexposed groups. At the completion of this
More informationInference on p, Comparisons on p, and ChiSquare for Contingency Tables and GOF
Inference on p, Comparisons on p, and ChiSquare for Contingency Tables and GOF 1. In a study of human blood types in nonhuman primates, a sample of 71 orangutans were tested and 14 were found to be blood
More informationCourse Text. Required Computing Software. Course Description. Course Objectives. StraighterLine. Business Statistics
Course Text Business Statistics Lind, Douglas A., Marchal, William A. and Samuel A. Wathen. Basic Statistics for Business and Economics, 7th edition, McGrawHill/Irwin, 2010, ISBN: 9780077384470 [This
More informationHow to Conduct a Hypothesis Test
How to Conduct a Hypothesis Test The idea of hypothesis testing is relatively straightforward. In various studies we observe certain events. We must ask, is the event due to chance alone, or is there some
More informationHypothesis Testing. Bluman Chapter 8
CHAPTER 8 Learning Objectives C H A P T E R E I G H T Hypothesis Testing 1 Outline 81 Steps in Traditional Method 82 z Test for a Mean 83 t Test for a Mean 84 z Test for a Proportion 85 2 Test for
More informationSECOND M.B. AND SECOND VETERINARY M.B. EXAMINATIONS INTRODUCTION TO THE SCIENTIFIC BASIS OF MEDICINE EXAMINATION. Friday 14 March 2008 9.009.
SECOND M.B. AND SECOND VETERINARY M.B. EXAMINATIONS INTRODUCTION TO THE SCIENTIFIC BASIS OF MEDICINE EXAMINATION Friday 14 March 2008 9.009.45 am Attempt all ten questions. For each question, choose the
More informationPart 2: Analysis of Relationship Between Two Variables
Part 2: Analysis of Relationship Between Two Variables Linear Regression Linear correlation Significance Tests Multiple regression Linear Regression Y = a X + b Dependent Variable Independent Variable
More informationResearch Methods & Experimental Design
Research Methods & Experimental Design 16.422 Human Supervisory Control April 2004 Research Methods Qualitative vs. quantitative Understanding the relationship between objectives (research question) and
More informationSimple Linear Regression in SPSS STAT 314
Simple Linear Regression in SPSS STAT 314 1. Ten Corvettes between 1 and 6 years old were randomly selected from last year s sales records in Virginia Beach, Virginia. The following data were obtained,
More information