Given the following information: the sampled population is normally distributed, n = 81, sample mean = 38.7, and the population standard deviation = 8.A. Construct a 95% confidence interval for the population mean and write a confidence statement.B. How large a sample should be taken if the population mean is to be estimated with 90% confidence to within 8 units?
You just recently read somewhere that the mean elevation drop for ski trails at eastern ski centers is at least 450 feet. You believe that the elevation is lower than 450 feet. Write the null and alternative hypotheses that would be used to test this staement.