A wine manufacturer is concerned that the percentage of alcohol in each bottle may not be the 13% as advertised on the bottle. A random sample of 31 bottles is tested. The average alcohol percentage is 12.58% and the standard deviation is 0.25%. Assume alcohol content is normally distributed.

How would you define the rejection region for this test at a = .001?

Select one:

a. t > 3.646 and t < -3.646

b. t > 2.33

c. t > 2.575

d. t > 2.728 and t < -2.728

e. t > 1.96 and t < -1.96