Question: This problem will give you practice in constructing confidence intervals and in discovering how to reduce their size (without sacrificing confidence). Smaller confidence intervals tell you the value of μ more precisely.
a. How wide is the 95 percent confidence interval about a sample mean when s^ = 4 and N = 4?
b. How much smaller is the 95 percent confidence interval about a sample mean when N is increased fourfold to 16 ( remains 4)?
c. Compared to your answer in part a, how much smaller is the 95 percent confidence interval about a sample mean when N remains 4 and s^ is reduced to 2?