Banking fees have received much attention during the recent economic recession as banks look for ways to recover from the crisis. A sample of 42 customers paid an average fee of 11.87$ per month on their interest-bearing checking accounts. Assume the population standard deviation is 1.78$. Complete parts a and b below.

Banking fees have received much attention during the recent economic recession as banks look for ways to recover from the crisis. A sample of 42 customers paid an average fee of $11.87 per month on their interest-bearing checking accounts. Assume the population standard deviation is $1.78. Complete parts a and b below a. Construct a 99% confidence interval to estimate the average fee for the population The 99% confidence interval has a lower limit of Sand an upper limit of $ (Round to the nearest cent as needed.) b. What is the margin of error for this interval? (Round to the nearest cent as needed)