FREQUENCY DISTRIBUTIONS What is a Frequency Distribution? What are Frequency Distributions Used For? Ways of Displaying Frequency Distributions Describing.

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FREQUENCY DISTRIBUTIONS What is a Frequency Distribution? What are Frequency Distributions Used For? Ways of Displaying Frequency Distributions Describing Frequency Distributions Frequency Distribution Statistics

What is a Frequency Distribution? raw score distribution: list of each individual’s score frequency distribution: list of each score that appears and how many times each score occurs

What are Frequency Distributions Used For? Summarize a large set of data. Describe the shape of a distribution. Needed for inferential statistics.

Ways of Displaying Frequency Distributions Table Frequency Polygon Histogram Bar Graph

Frequency Distribution Table xf

Frequency Polygon Best for quantitative/continuous data. Study Time in Hours f

Histogram Best for quantitative/continuous data. Study Time in Hours f

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

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.

Describing Frequency Distributions symmetrical: same on both sides

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

kurtosis: steepness leptokurtic platykurtic mesokurtic

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