The Consumer Reports article described in Exercise 52 continued their investigation of washing machines. One of the

Question:

The Consumer Reports article described in Exercise 52 continued their investigation of washing machines. One of the variables the article reported was "cycle time," the number of minutes it took each machine to wash a load of clothes. Among the machines rated good to excellent, the 98% confidence interval for the difference in means cycle time
(µTop - µFront) IS (-40, -22).
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 µTop - µFront = 0, what's the corresponding alpha level?