AP PSYCH: Statistics

Frequency Distribution

Plotting how often certain phenomena occur.

Normal distribution

An arrangement of data values that clusters around the middle where the mean is located. The values further away from the mean, taper off equally on both sides, giving us a bell shape curve (bell curve). Outliers skew the data.

Skewed Graph

Median, mean, and mode do not line up. The mode is ALWAYS going to be the highest point in the curve. In a skewed graph, the MEDIAN is the MOST useful measure of central tendency.

Standard Deviation

A measure of spread (how close the values in a data set are to the mean). Squished up (closer) against the mean is SMALL deviation, spread out from the mean is LARGE deviation. To find the largest standard deviation: look at the data set with the greatest/largest range. To find the smallest standard deviation: look at the data set with the smallest range. Range = Largest\ number - Smallest\ number