Hypothesis Testing for the Mean with Large Samples
When the sample size we use to test our hypothesis is large (n ≥ 30), we can rely on our old friend the central limit theorem which we met in Chapter 13. However, we still have two cases to consider—whether σ, the population standard deviation, is known or unknown.
When Sigma Is Known
To demonstrate this type of hypothesis test, I’ll use the following story.
One of the most feared phrases a husband can hear from his wife is, “Honey, let’s go on a diet together.” I should have been suspicious of Debbie’s motives when she suggested we go on the low-carbohydrate diet, especially because she wears size 2 pants. But I guess I could stand to lose a few pounds, so in a weak moment, I agreed. After ...