BUS/ST 350 Exam 1 Fall 2011

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1 BUS/ST 350 Exam 1 Fall 2011 Name Lab Section ID # INSTRUCTIONS: Write your name, lab section #, and ID# above. Note the statement at the bottom of this page that you must sign when you are finished with the exam. Supply the following information on SIDE ONE of the scantron sheet: Enter your name (last name first!) in the "name" section; no nicknames! FILL IN THE BUBBLES. Enter your 3 digit lab section number in the "special code" section. FILL IN THE BUBBLES. Enter your student identification number in the "identification number" section. FILL IN THE BUBBLES. IMPORTANT! BUBBLE IN the version number (either "1", "2"or "3") of your copy of the exam in the section marked "GRADE OR EDUCATION". There are 17 multiple choice questions. On the test circle the letter that corresponds to the answer you select. Also indicate your selection on the opscan sheet. Use a #2 pencil! For each wrong answer 5 points will be subtracted from 100. When you are finished: separate your scantron sheet from the test! i) place the 1st page of your test in the proper lab section stack on the auditorium stage ii) place your scantron sheet in the folder labeled with your version of the test. GOOD LUCK!! Statement of academic honesty: I have neither given assistance to another student nor received assistance from another student while taking this exam. Signed 1

2 1) The Human Resources Department of a large corporation maintains records on its employees. Data are maintained of the following variables: Age, Employment Category, Education, Whether or not the employee participates in a wellness program, and Dollar amount deducted from paycheck for benefits. Which of these variables are categorical? A) All of these B) Employment Category, Education, and Whether or not the employee participates in a wellness program C) Age, Employment Category, and Education D) Education, Whether or not the employee participates in a wellness program, and Paycheck benefit deductions E) None of these 2) An advocacy group is investigating whether gender has an effect on job category in large investment firms. The advocacy group surveyed a sample of firms with the results shown below. Which of the following statements is true about gender and job category? A) The segmented bar chart is not appropriate for these data. B) A greater percentage of males are executives compared to females. C) A smaller percentage of females are clerical compared to males. D) A greater percentage of females are executives compared to males. E) Job category appears to be independent of gender. 3) A researcher is conducting a study on Internet use. He decides to first categorize the population by education level (high school, college graduate, advanced degree, etc.) and then survey a select number from each category. This sampling strategy is called A) Stratified B) Systematic C) Random D) Cluster E) Convenience

3 4) In their October 2010 issue, Consumer Reports evaluated the price and performance of 23 models of cordless phones. Computer output gives the summary statistics for the prices ($) shown in the table. Based on these results, which of the following is true? Min Q1 Median Q3 Max Mean SD A) The distribution is skewed to the left. B) The distribution is symmetric. C) The mean is a better measure of center for these data than the median. D) The standard deviation is larger than the range. E) The distribution is skewed to the right. 5) Boxplots of earnings per share (EPS) data for a sample of retail company stocks and a sample of energy company stocks are shown below. The boxplots are outlier boxplots that use 1.5*IQR to determine outliers. Which of the following statements is correct? A) The mean is higher for energy stocks compared to retail stocks. B) The EPS data are more variable for retail stocks than for energy stocks. C) The median EPS is higher for retail stocks compared to energy stocks. D) The IQR for the EPS data is larger for retail stocks than for energy stocks. E) The median EPS is higher for energy stocks compared to retail stocks. 6) The five-number summary of credit hours for 24 students in a statistics class is: From this information, we know that A) there is at least one low outlier in the data. B) there are no outliers in the data. C) there are both low and high outliers in the data. D) there is at least one high outlier in the data. E) None of the above.

7) In an analysis of the miles per gallon (mpg) of different models of automobiles, the Honda Civic has a z-score of +2.2. This means that... A) the mpg for Honda Civics is 2.2 times the average mpg.

4 7) In an analysis of the miles per gallon (mpg) of different models of automobiles, the Honda Civic has a z-score of This means that... A) the mpg for Honda Civics is 2.2 times the average mpg. B) the mpg for Honda Civics is 2.2 standard deviations above the average mpg. C) Honda Civics get 2.2 mpg more than the average mpg. D) Honda Civics have a standard deviation of 2.2 mpg. E) Honda Civics get 2.2 miles per gallon. 8) The standard deviation of the data displayed in this dotplot is most likely to be A) 5. B) 6. C) 20. D) 10. E) 18. 9) Which is true of the data shown in the histogram? I. The distribution is skewed to the right. II. The mean is smaller than the median. III. We should use median and IQR to summarize these data. A) III only B) I only C) I, II, and III D) II and III only E) II only 10) A sociologist recently conducted a survey of citizens over 60 years of age who have net worths too high to qualify for Medicaid but have no private health insurance. The ages of the 25 uninsured senior citizens were as follows: Suppose the mean and standard deviation are and 9.75, respectively. If we assume that the distribution of ages is mound-shaped and symmetric, what percentage of the respondents will be between and years old? A) approximately 81.5% B) approximately 84% C) approximately 95% D) approximately 68%

5 11) Twenty-four workers were surveyed and asked how long it takes them to travel to work each day. The data below are given in minutes Which of the following shows the data in a stem-and-leaf plot? A) B) C) D) E) ) After a hurricane, a disaster area is divided into 200 equal grids. Thirty of the grids are to be randomly selected and analyzed in detail for storm damage. Select the numbers of the first five grids that belong to the sample using the random numbers given below A) 163, 487,693, 890, 169 B) 16348, 76938, 90169, 51392, C) 890, 169, 539, 255, 887 D) 163, 169, 15, 92, 97 E) 16, 38, 48, 76, 93

6 13) A simple random sample of size 8 is defined to be A) A sample of size 8 chosen in such a way that every possible group of 8 units in the population has an equal chance to be the sample actually selected. B) a sample of size 8 chosen in such a way that every individua l unit in the population has a nonzero chance of being selected. C) A sample of size 8 chosen in such a way that every possible group of 8 units in the population has a nonzero chance to be the sample actually selected. D) A sample of size 8 chosen in such a way that every individual in the population has the same chance of being selected. E) All of the above. They are essentially equivalent definitions. 14) Your Stats teacher tells you your test score was the 3rd quartile for the class. Which is true? I. You got 75% on the test. II. Your test score is better than 75% of the test scores. III. Your test score is greater than or equal to the median test score. A) III only B) II only C) I only D) II and III E) none of these 15) Book sales A publishing company pays its sales staff $600 a week plus a commission of $0.50 per book sold. For example, a salesman who sold 440 books earned (440) = $820. The table shows summary statistics for the number of books the large sales staff sold last week. The newest employee sold 1288 books last week; the corresponding z-score for the number of books she sold is What was the z-score of the amount she was paid? A) B) C) D) E) ) At the U.S. Open Tennis Championship a statistician keeps track of every serve that a player hits during the tournament. The statistician reported that the mean serve speed of a particular player was 98 miles per hour. Suppose that the statistician indicated that the serve speed distribution was skewed to the left. Which of the following values is most likely the value of the median serve speed? A) 88 mph B) 98 mph C) 93 mph D) 83 mph E) 103 mph

7 17) Just how accurate are the weather forecasts we hear every day? The table below compares the daily forecast with a city's actual weather for a year. Forecast Actual Weather Rain No rain Rain No rain GIven that rain was forecast, what proportion of the time did it actually rain? A) 0.17 B) 0.62 C) 0.38 D) 0.08 E) 0.92

8 Asnwer Key: 1. B 2. B 3. A 4. E 5. C 6. B 7. B 8. D 9. D 10. A 11. A 12. D 13. A 14. D 15. A 16. E 17. C

BUS/ST 350 Exam 3 Spring 2012

BUS/ST 350 Exam 3 Spring 2012 Name Lab Section ID # INSTRUCTIONS: Write your name, lab section #, and ID# above. Note the statement at the bottom of this page that you must sign when you are finished with