A sample of 81 observations has been selected to test whether the population mean is smaller than 15. The sample showed an average of 14.6 and a standard deviation of 2.1. You want to test this...

A sample of 81 observations has been selected to test whether the population mean is smaller than 15. The sample showed an average of 14.6 and a standard deviation of 2.1. You want to test this hypothesis at 95% level of confidence. Compute the p-value for this test