Test the hypothesis that the population mean duration of the bus tours in Example 8.10 is 60 minutes, H0:  = 60. Use the sample mean given in Example 8.12 and apply a 5 per cent level of significance.

H0:  = 60 minutes H1:   60 minutes The level of significance,  = 0.05 From Example 8.12 we know that the probability that the sample mean, 61.87, belongs to a sampling distribution with a mean of 60 and a standard error of 0.85 is 0.0139 or 1.39 per cent. Since this is less than 21 2 per cent we can reject the null hypothesis at the 5 per cent level.