Section 8.4

#13. Given info: n = 40, X-bar = 58.3, sigma = 9.5

We are to "test the claim that the population mean is equal to 60 ...," so one of our hypotheses must be "µ = 60 ." This must be H_{0}, since H_{0} must have an equal sign in it. That leaves "µ ≠ 60" as the H_{1}. Notice that we are given a value for sigma, so we can use a z-test. Also, the sample size is large, so we need not make any assumptions of normality.

Now see if you can do the test.

Section 8.5

#17. Given info: n = 106, X-bar = 98.20, s = 0.62

We are to "test the claim that the mean body temperature is less than 98.6," so one of our hypotheses must be "µ < 98.6." This must not be H_{0}, since H_{0} must have an equal sign in it. That leaves "µ = 98.6 " as the H_{0}. Notice that we are not given a value for sigma, so we must use a t-test. Also, the sample size is large, so we need not make any assumptions of normality.

Now see if you can do the test.