then the hypothesized value of μ will not be (will be) in a C = 1 – α confidence interval. In this
problem, 120 was in the C = 0.95 confidence interval and a significance test at α = 0.05 failed to
reject the null as expected.
e. For the one-sided test, t = 1.90, df = 19 0.025 < P -value < 0.05
(On the TI-83/84, we find P -value = tcdf(1.90,100,19) = 0.036. )
For the two-sided test, we concluded that we did not have evidence to reject the claim of the
manufacturer. However, for the one-sided test, we have stronger evidence (P < 0.05) and would
conclude that the average drying time is most likely greater than 120 minutes.