Chapter 8.2, Problem 1SE

Find the interval $\left[\mu -z\frac{\sigma }{\sqrt{n}},\mu +z\frac{\sigma }{\sqrt{n}}\right]$ within which 90 percent of the sample means would be expected to fall, assuming that each sample is from a normal population.

1. a. μ = 100, σ = 12, n = 36
2. b. μ = 2,000, σ = 15, n = 9
3. c. μ = 50, σ = 1, n = 25