Chapter 11, Problem 5P

A sample of $n=9$ individuals participates in a repeated-measures study that produces a sample mean difference of $M_d=4.25$ with $SS=128$ for the difference scores.

a. Calculate the standard deviation for the sample of difference scores. Briefly explain what is measured by the standard deviation.

b. Calculate the estimated standard error for the sample mean difference. Briefly explain what is measured by the estimated standard error.