A 3-column table with 4 rows. Column 1 has entries Computer repair, sales tax, gratuity, shipping. Column 2 is labeled Store A with entries 1,200 dollars, 6 percent, 15 percent, Free. Column 3 is labeled Store B with entries 1,350 dollars, 7 percent, 15 percent, 2 percent of total price. What is the cost of the repair and sales tax combined at Store B?

Arandom sample of 15 observations is used to estimate the population mean. the sample mean and the standard deviation are calculated as 172 and 63, respectively. assume that the population is normally distributed. a. with 99 confidence, what is the margin of error for the estimation of the population mean? b. construct the 99% confidence interval for the population mean. c. construct the 95% confidence interval for the population mean. d. construct the 83% confidence interval for the population mean. hint: you need to use excel function =t. inv.2t to find the value of t for the interval calculation.