A bank manager wants to know the mean amount owed on credit card accounts that become delinquent. A random sample of 100 delinquent credit card accounts taken by the manager produced a mean amount owed on these accounts equal to $2640. The population standard deviation was $578.
a. What is the point estimate of the mean amount owed on all delinquent credit card accounts at this bank?
b. Construct a 97% confidence interval for the mean amount owed on all delinquent credit card accounts for this bank.