For the situation in Exercise 25, let msto represent the mean square total from the sample ANOVA table.
a. Write msto as a function of msb and msw, and use the results of Exercise 25(c) to find E[msto].
b. Show that E[msto] ≈ S2 if n and N are large.
c. Show that

is an unbiased estimator of S2.