The local swim team is considering offering a new semiprivat

      The local swim team is considering offering a new semi-private class aimed at entry-level swimmers, but needs at minimum number of swimmers to sign up in order to be cost effective. Last year’s data showed that during 8 swim sessions the average number of entry-level swimmers attending was 15. Suppose the instructor wants to conduct a hypothesis test. The alternative hypothesis for this hypothesis test is: \"the population mean is less than 15\". The sample size is 8, s is known, and alpha =.05, the critical value of z is _______.

Solution

Since the test is left tailed and the sample size is samll, we use the t distribution, with n-1=8 degrees of freedom. The critical value is -1.8595.