Arandom sample of 22 observations is used to estimate the population mean. the sample mean and the sample standard deviation are calculated as 107.5 and 22.50, respectively. assume that the population is normally distributed. [you may find it useful to reference the t table.] a. construct the 90% confidence interval for the population mean. (round intermediate calculations to at least 4 decimal places. round "t" value to 3 decimal places and final answers to 2 decimal places.) b. construct the 95% confidence interval for the population mean. (round intermediate calculations to at least 4 decimal places. round "t" value to 3 decimal places and final answers to 2 decimal places.) c. use your answers to discuss the impact of the confidence level on the width of the interval. as the confidence level increases, the interval becomes wider. as the confidence level increases, the interval becomes narrower.