Assistance needed.

A 52-year-old client has come to you for assistance with funding her HSA. Her doctor has told her that she will be facing knee replacement surgery within the next five years. She was also told that her out-of-pocket expenses (deductibles, copays, and various other uncovered expenses including rehabilitation) for the operation would total $ 4,000 if the operation happened today. Her open enrollment period is currently open. She plans to wait exactly five years for the surgery.

How much money should she contribute on a monthly basis if the account pays a stated rate (APR) of 4% compounded quarterly. To determine her out-of-pocket expenses at the time of her surgery, inflate the current cost by an effective annual rate of 7%.