Unit 2: Descriptive Statistics

Outline


2.1       Types of Figures

•   Histogram: Continuous
•   Bar Graph: Categorical
•   Frequency Polygon


2.2       Shapes of Curves

•   The Normal Curve
•   Right and Left Skew


2.3       Measures of Central Tendency

•   Mean: The average
•   Median: The middle
•   Mode: The highest frequency


2.4       Measures of Variability

•   Range: the difference between the highest score and the lowest score in a set of scores.
•   Interquartile Range: The range of the middle 50% (IQR = Q3 – Q1).
•   Standard Deviation: The measure that indicates the degree to which the scores vary from the mean


2.5       The 68-95-99.7 Rule for Normal Distributions

•   68% of scores lie within one standard deviation from the mean.
•   95% of scores lie within two standard deviations from the mean.
•   99.7% of scores lie within three standard deviations from the mean.


Resources

Lecture
Notes

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Work
Sheet

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Unit
Project

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Study
Guide

Self-Scorers:
Descriptive Statistics

Do not request access.
Use your google account (or create one for free).
Open the spreadsheet, click on <File> and <Make a copy>.
Enter your data. Errors will be highlighted.
When the project is complete/correct, record your receipt number.