For Exercises 15–26, do the following:
25. A random sample of size 9 from a normal population yields and . Researchers are interested in finding whether the population mean differs from 0, using level of significance .
9.4.25
(a) . Reject if the (b) (c) 0.0003 (d) Since the is , the conclusion is reject . There is evidence at the 0.05 level of significance that the population mean differs from 0.