In the formula for estimating the population variance from the scores in a sample, the sum of squared deviations is divided by:
A)the number of participants in the sample
B)the number of participants in the sample minus one
C)the number of participants in the population
D)the number of participants in the population minus one

Question

Quizplus · Accepted Answer

When estimating the population variance from a sample, we divide the sum of squared deviations by the degrees of freedom, which is equal to the sample size minus one (n-1). This corrects for the fact that using the sample mean as an estimate of the population mean reduces the variability in the data, and we don't want to overestimate the population variance as a result. Therefore, the correct formula is (SSD)/(n-1), where SSD is the sum of squared deviations and n is the sample size.

In the Formula for Estimating the Population Variance from the Scores