Question

# The First Chicago Bank is reviewing its service charges and interest-paying policies on checking accounts. The...

The First Chicago Bank is reviewing its service charges and interest-paying policies on checking accounts. The daily balance of a checking account is defined to be the balance in the checking account at 2:00pm.
The bank has found that for all personal checking accounts the mean of all the daily balances is \$900 and the standard deviation is \$125.
In addition, the distribution of personal checking account daily balances can be approximated very well with a normal model.

QUESTION: What percentage of the bank's customers carry daily balances between \$700 and \$1,000?(Use 2 decimal places in your answer. Note that the answer is requested as a percent, that is, a value between 0 and 100).

QUESTION 2: The bank is considering paying interest to customers carrying daily checking account balances in excess of a certain amount. If the bank does not want to pay interest to more than 4% of its checking account customers, what is the minimum daily balance on which it should be willing to pay interest?

QUESTION: What percentage of the bank's customers carry daily balances between \$700 and \$1,000?(Use 2 decimal places in your answer. Note that the answer is requested as a percent, that is, a value between 0 and 100).

 µ 900 σ 125 x 700 z = (x - µ)/σ -1.6 p-value 0.054799 x 1000 z = (x - µ)/σ 0.8 p-value 0.788145 Required probability 73.33%

QUESTION 2: The bank is considering paying interest to customers carrying daily checking account balances in excess of a certain amount. If the bank does not want to pay interest to more than 4% of its checking account customers, what is the minimum daily balance on which it should be willing to pay interest?

 z -1.75069 x 681.164