Question

CU headphone company wants to estimate the proportion of people having a wireless headphone. To construct a 93% confidence interval that extends at most +/- 0.04, how many people do they need to sample? ABC state park wants to know the average number of visitors per day. It is assumed that the number of visitors per day follows a normal distribution. They take a sample of 8 days and from them finds a mean of 128 and a standard deviation of 38. Construct a 95% confidence interval for the population mean number of visitors per day. 128 +/-