3)Banking fees have received much attention during the recent economic recession as banks looked for ways to
recover from the crisis. A sample of 30 customers paid an average fee of $12.55 per month on their level interest-bearing checking accounts. Assume the population standard deviation is $1.75.
3a) construct a 95% confidence interval to estimate the average fee for the population.
3b) what is the margin of error for this interval?
Statistics and Probability