A survey of 48 randomly selected iPhone owners showed that the purchase price has a mean of $670 with a sample standard deviation of $23. (Use z Distribution Table.) a. Compute the standard error of...

Extracted text: A survey of 48 randomly selected iPhone owners showed that the purchase price has a mean of $670 with a sample standard deviation of $23. (Use z Distribution Table.) a. Compute the standard error of the sample mean. (Round your answer to the nearest whole number.) Standard error b. Compute the 98% confidence interval for the mean. (Use tDistribution Table.) (Round your answers to 3 decimal places.) The confidence interval is between and c. To be 98% confident, how large a sample is needed to estimate the population mean within $8? (Round up your answer to the next whole number.) Sample size