Reconsider the paint-drying situation of Example 8.2, in which drying time for a test specimen is normally distributed with . The hypotheses versus are to be tested using a random sample of observations.

a. How many standard deviations (of ) below the null value is ?

b. If , what is the conclusion using ?

c. What is a for the test procedure that rejects H0 when

?

d. For the test procedure of part (c), what is b(70)?

e. If the test procedure of part

(c) is used, what n is necessary to ensure that ?

f. If a level .01 test is used with , what is the probability of a type I error when ?