Describing Data and Distributions

Question 1

Mean Deviation

Answer 1

An infrequently used measure of dispersion based, in part, on the absolute deviations from the mean of the distribution. Also known as the average deviation.

Question 2

Bimodal Distribution

Answer 2

A distribution with two modes.

Question 3

Central Tendency

Answer 3

The center or typicality of a distribution. The three most common measures of central tendency are the mean, median, and mode.

Question 4

Dispersion

Answer 4

The extent to which the scores in a distribution are spread around the mean value or throughout. The two most commonly used measures of dispersion are the variance and the standard deviation.

Question 5

Mean

Answer 5

The mean is calculated by summing all the scores in a distribution and dividing the sum by the total number of cases in the distribution.

Question 6

Median

Answer 6

The score that divides a distribution in half; the point above and below which one-half of the scores or values are located. The formula for the median is positional and will tell you the position of the median in the distribution, not its value.

Question 7

Mode

Answer 7

The response or value that appears most frequently in a distribution. The mode is the only measure of central tendency that is appropriate for nominal level data.

Question 8

Mu

Answer 8

The mean of a population.

Question 9

Range

Answer 9

A statement of the difference between the highest and lowest scores or values in a distribution. As a measure of dispersion or variability, the range is simple to calculate, but it doesn’t say much about the distribution.

Question 10

Standard Deviation

Answer 10

The standard deviation is the square root of the variance.

Question 11

Unimodal Distribution

Answer 11

A distribution with only one mode.

Question 12

Variance

Answer 12

The variance is equal to the standard deviation squared.