d) For what values of X should Ho be rejected so that the level of the test will be 0.05? What will the power then be? e) How large of a sample is needed so that a 5% level test has power 0.85? The mean drying time of a certain paint in a certain application is 12 minutes. A new additive will be tested to see if it reduces the drying time. Eight-one specimens will be painted, and the sample mean drying time will be computed. Assume the population standard deviation of drying times is 1.7 minutes. Let u be the mean drying time for the new paint. Assume that unknown to the investigator, the true mean drying time of the new paint is 11.5 minutes. a) What are the null and alternative hypotheses for this hypothesis test? b) It is decided to reject Ho if X < 11.69. Find the level and the power of this test. c) For what values of X should Ho be rejected so that the power of the test will be 0.90? What will the level then be?