Question: 13 A random sample of 8 observations was drawn from a normal population. The sample mean and sample standard deviation are \(\bar{X}\) = 40 and s = 10.

a) Estimate the population mean with 95% confidence.

b) Repeat part a assuming that you know that the population standard deviation is σ = 10.

c) Explain why the interval estimate produced in Part b is narrower than that in Part a