Psychological Statistics Chapter 4
variability -
provides a quantitative measure of the differences between scores in a distribution and
describes the degree to which the scores are spread out or clustered together
range -
Xmax-Xmin
URL for Xmax - LRL for Xmin
deviation or deviation score -
the difference between a score and the mean
X-mu
variance -
equals the mean of the squared deviations
standard deviation -
the square root of the variance and provides a measure of the standard or average distance
from the mean
sum of squares -
the sum of the squared deviated scores
population variance -
represented by lower case sigma squared and equals the mean squared distance from the
mean.
population standard deviation -
