The Consumer Reports article described in Exercise 51 also listed the fat content (in grams) for samples of beef and meat hot dogs. The resulting 90% confidence interval for µMeat - µBeef is (-6.5, -1.4).
a) The endpoints of this confidence interval are negative numbers. What does that indicate?
b) What does the fact that the confidence interval does not contain 0 indicate?
c) If we use this confidence interval to test the hypothesis that µMeat - µBeef = 0, what's the corresponding alpha level?