4. (10 pts) Sunny and Destry are proud new parents and have decided to start saving to build up a college fund, beginning with their first annual deposit to be made on their baby's first birthday and continuing each birthday until the child is 21 years old. Their plans include the following assumptions: - Their child will begin drawing funds when it turns 18 years old. - In year 18,$10,000 will be withdrawn. - The amount withdrawn will increase by $1,000 each year for years 19-23 (for a total of 6 years' worth of withdrawals - in case their child decides to go to graduate school as well.) They plan on an interest rate of 3.5% per year. Draw a diagram of the cash flow. How much will they need to save each year to cover their planned college costs