A state transport official claims that the mean waiting time at exit booths from a toll road near the capitol is no more than 0.40 minutes. For a sample of motorists exiting the toll road, it was found that the mean waiting time was 0.46 minutes, with a standard deviation of 0.16 minutes. At the 0.05 level of significance, can we reject the official's claim

How many were in the sample?





a right-tailed test.

If there is no sample size given, we can try this.

Test statistic:

Using a .05 alpha level, the rejection region is

Clearly, 375 is not in the rejection region. Therefore, we fail to reject the null hypothesis.