AP PSYCHOLOGY

Detailed explanation-1: -The variance and the standard deviation are measures of the spread of the data around the mean. They summarise how close each observed data value is to the mean value. In datasets with a small spread all values are very close to the mean, resulting in a small variance and standard deviation.

Detailed explanation-2: -Range, interquartile range, and standard deviation are the three commonly used measures of dispersion.

Detailed explanation-3: -The standard deviation is a summary measure of the differences of each observation from the mean. If the differences themselves were added up, the positive would exactly balance the negative and so their sum would be zero. Consequently the squares of the differences are added.

Detailed explanation-4: -Standard deviation, Range, Mean absolute difference, Median absolute deviation, Interquartile change, and Average deviation are examples of measures of dispersion.