1 / 15

FREQUENCY DISTRIBUTIONS

FREQUENCY DISTRIBUTIONS. raw score distribution: list of each individual’s score frequency distribution: list of each score that appears and how many times each score occurs. Uses of Frequency Distributions. Summarize a large set of data. Describe the shape of a distribution.

Download Presentation

FREQUENCY DISTRIBUTIONS

An Image/Link below is provided (as is) to download presentation 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. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. FREQUENCY DISTRIBUTIONS • raw score distribution: list of each individual’s score • frequency distribution: list of each score that appears and how many times each score occurs

  2. Uses of Frequency Distributions • Summarize a large set of data. • Describe the shape of a distribution. • Needed for inferential statistics.

  3. A Raw Score Distribution 7 5 3 1 7 2 3 5 2 6 6 2 3 4 7 7 5 3 1 4 2 6 1 4 5 7 2 4 3 4 2 2 1 1 3 5 5 3 2 4 2 3 5 1 4 4 2 1 3 5

  4. Frequency Distribution Table x f 7 5 6 3 5 8 4 8 3 9 2 10 1 7

  5. 15 f 10 5 0 1 2 3 4 Frequency Polygon Best for quantitative/continuous data. Study Time in Hours

  6. 15 f 10 5 0 1 2 3 4 Histogram Best for quantitative/continuous data. Study Time in Hours

  7. Bar Graph Best for qualitative/discrete variables. 15 f 10 5 Ed. Bus. A&S AST College

  8. Guidelines for Graphs • Label units. • Make axes proportional (y axis should be 2/3 to 3/4 length of x axis). • Make bars equal width. • Keep it simple.

  9. Describing Frequency Distributions symmetrical: same on both sides

  10. skewed: scores piled on one side body tail positive skew negative skew

  11. kurtosis: steepness leptokurtic platykurtic mesokurtic

  12. Frequency Distribution Statistics • relative frequency: proportion of scores that are x • cumulative frequency: number of scores up to and including x • percentile rank: percentage of scores up to and including x • percentile: x score at a percentile rank

  13. Cumulative Frequency x f cf 7 5 50 6 3 45 5 8 42 4 8 34 3 9 26 2 10 17 1 7 7 always equals N, total # of scores add the frequencies start at the bottom score

  14. Relative Frequency divide each frequency by N x f rf 7 5 .10 6 3 .06 5 8 .16 4 8 .16 3 9 .18 2 10 . 20 1 7 .14 5/50 = .10 3/50 = .06 8/50 = .16 8/50 = .16 9/50 = .18 10/50 = .20 7/50 = .14

  15. Percentile Rank divide cf by N and multiply by 100 x f cf pr 7 5 50 100 6 3 45 90 5 8 42 84 4 8 34 68 3 9 26 52 2 10 17 34 1 7 7 14 100th %ile = 7 90th %ile = 6 84th %ile = 5 68th %ile = 4 52nd %ile = 3 34th %ile = 2 14th %ile = 1

More Related