a) In order to compare the means of two populations (each of
them is approximately normally distributed), independent random
samples are selected from each population, with the following
results: n1 = 12, x ̄1 = 7.6, s1 = 0.36, n2 = 17, x ̄2 = 6.5, s2 =
0.19. You are told that σ21 = σ22=
σ2. Based on the given data information, find the pooled
estimate for σ2
b) For Question 16, you are told that σ21
= σ22=...