Problem 21-16 Optimal Cash Balances (LO4) Suppose that your weekly cash expenses are $80. Every time you withdraw money from the automated teller at your bank, you are charged $0.25. Your bank account pays interest of 3% annually a. How often should you withdraw funds from the bank? (Round your answer to 2 decimal places.) You should go to the bank about once every week(s) b. What is the optimal-sized withdrawal? (Round your answer to the nearest whole dollar) Optimal-sized withdrawal C. What is your average amount of cash on hand? (Round your answer to the nearest whole dollar.) Average amount of cash on hand $