Psych Stats (Central Tendency and Variability)

Central Tendency

is a statistical measure to determine a single score that defines the center of a distribution.

Arithmetic Mean, Median, Mode

Three most often used measures of central tendency are

Mean

Arithmetic Mean is also called

Arithmetic Mean

the sum of the scores divided by the number of scores

Sensitive

The mean is ____ to the exact value of all the scores in the distribution

extreme scores

The mean is very sensitive to

Overall Mean

also known as Weighted Mean

Median

the centermost score if the number of scores

Median (2)

Midpoint of the list

less sensitive

The median ____ than the mean to extreme scores

Mode

the score or category that has the greatest frequency

No Mode/ None

What if all the scores in the distribution have the same frequency

The Tail

Mean follows the

In between

Median stays

The Peak

Mode stays at

Variability

measures of ____ quantify the extent of dispersion

Range, Standard Deviation, Variance

three most often used measures of variability

Range

difference between the highest and lowest score in the distribution

Standard Deviation

measures how spread out the data is from the mean (average)

Variance

a set of scores is just the square of the standard deviation