Variable: characteristic that varies from one individual to another in the population

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Lesley York
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1 Goals: Recognize variables as: Qualitative or Quantitative Discrete Continuous Study Ch. 2.1, # 1 13 : Prof. G. Battaly, Westchester Community College, NY Study Ch. 2.1, # 1 13 Variable: characteristic that varies from one individual to another in the population 1. Qualitative: value is NOT a number eg: hair color, type of battery, etc. 2. Quantitative: value IS a number eg: weight, height, minutes, etc. : Prof. G. Battaly, Westchester Community College, NY G. Battaly

2 2. Quantitative: value IS a NUMBER eg: weight, height, minutes, etc. a) Discrete: possible values can be listed (finite) eg: counts b) Continuous: possible values on an interval (not finite) eg: 60gm < NSWO mass < 110gm Statistical methods are designed with basic assumptions which depend on the type of data > analyze qualitative data differently from continuous data : Prof. G. Battaly, Westchester Community College, NY Saw whets qualitative or quantitative? Broad winged Hawks type of variable? qualitative quantitative? discrete continuous y axis? date dots (2014 data) Species codes "Since 1971" : Prof. G. Battaly, Westchester Community College, NY G. Battaly

Goals: 1. Organize data by grouping 2. Find frequencies and relative frequencies of groups 3. Construct a frequency distribution table 4. Graph the data to display groups for easy comparison Study Ch.

3 Goals: 1. Organize data by grouping 2. Find frequencies and relative frequencies of groups 3. Construct a frequency distribution table 4. Graph the data to display groups for easy comparison Study Ch. 2.2 #15 19, 23, 29 : Prof. G. Battaly, Westchester Community College, NY Study Ch. 2.2 #15 19, 23, 29 As the number of data items increases, we need a way to 1. organize and manage how we think about the data 2. determine how the data is distributed What can you tell from this data set without organization? : Prof. G. Battaly, Westchester Community College, NY G. Battaly

4 Relative Frequency Distribution: Listing of distinct values and their relative frequencies. Relative frequency = Frequency No of Observations : Prof. G. Battaly, Westchester Community College, NY =COUNTIF(E$2:N$6,"=WE") Relative Frequency Distribution: Listing of distinct values and their relative frequencies. Relative frequency = Frequency No of Observations Frequencies show that there are more states in the southern region than in other regions, and... : Prof. G. Battaly, Westchester Community College, NY =COUNTIF(E$2:N$6,"=WE") G. Battaly

5 Graphs: visual representation of the numbers 1. South has most states 2. Northeast has the least 3. West and Midwest have about the same : Prof. G. Battaly, Westchester Community College, NY Qualitative Data: display using 1. Pie Chart, circle w proportions 2. Bar Graph, separate bars m&m colors : Prof. G. Battaly, Westchester Community College, NY G. Battaly

Diagrams and Graphs of Statistical Data

Diagrams and Graphs of Statistical Data One of the most effective and interesting alternative way in which a statistical data may be presented is through diagrams and graphs. There are several ways in