An important factor in selling a residential property is the number of times real estate agents show a home. A sample of 20 homes recently sold in the Buffalo, New York, area revealed the mean number of times a home was shown was 18 and the standard deviation of the sample was 7. (Use t Distribution Table & z Distribution Table.) Required: a. What is the margin of error for a 98% confidence interval? Note: Round your answer to 3 decimal places. Margin of error b. What is the 98% confidence interval for the population mean? Note: Round your answers to 2 decimal places. Confidence interval for the population mean is between and