For each situation in Exercise 7.9, find an interval that contains (approximately or exactly) 99.73 percent of

Question:

For each situation in Exercise 7.9, find an interval that contains (approximately or exactly) 99.73 percent of all the possible sample means. In which cases must we assume that the population is normally distributed? Why?
a. μ = 10, σ = 2, n = 25
b. μ = 500, σ = .5, n = 100
c. μ = 3, σ = .1, n = 4
d. μ ± = 100, σ = l, n = 1,600