Banking fees have received much attention during the recent economic recession as banks look for ways to recover from the crisis. A sample of 36 customers paid an average fee of $12.42 per month on their interest-bearing checking accounts. Assume the population standard deviation is $1.91. 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 $ ] and 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.)