SP 225 Lecture 5

1 / 17

# SP 225 Lecture 5 - PowerPoint PPT Presentation

SP 225 Lecture 5. Percentages, Proportions, Rates of Change and Frequency Distributions. Proportion. The number of cases in one category of a variable divided by the number of cases in all categories of a variable. Rates. Definition: A proportion written with a base other than 1. Percentage.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

## PowerPoint Slideshow about 'SP 225 Lecture 5' - jena

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

### SP 225Lecture 5

Percentages, Proportions, Rates of Change and Frequency Distributions

Proportion
• The number of cases in one category of a variable divided by the number of cases in all categories of a variable
Rates
• Definition: A proportion written with a base other than 1
Percentage
• Definition: a rate written with a base of 100
Percentage Change
• Definition: A statistic that tells how much a variable has changed over time.
Frequency Distribution

Definition: A table that summarizes the distribution of a variable by reporting the number of cases contained in each of its categories

Making Decisions Based on Ordinal Data
• Cannot truly calculate an average score
• Cannot directly compare categories
Frequency Tables for Interval/Ratio Data
• Group categories
• Groups represent ranges of values
Constructing a Frequency Table
• Decide upon a number of groups
• Find the range of data by subtracting the minimum value from the maximum value
• Divide the range by the number of groups to get the minimum group size
• Define the lower limit of the lower interval and begin building the groupings
• Count the number of cases in each group
Example Frequency Table

5 10 17 13

8 12 19 22

15 3 9 2

14 16 20 19

18 7 14 23

14 21 28 18

Constructing a Frequency Table in SPSS
• Use recode command to group data
• Groups must be created manually before frequency table is constructed