Final answer:
Mark Welsh will have $8,113.14 in his account at the end of 3 years after depositing $7,200 in an account earning 4% interest compounded quarterly.
Step-by-step explanation:
When Mark Welsh deposits $7,200 into an account earning 4% interest compounded quarterly, to find out how much money will be in the account at the end of 3 years, we use the formula for compound interest. The compound interest formula is A = P(1 + r/n)^(nt), where A is the amount of money accumulated after n years, including interest, P is the principal amount (the initial amount of money), r is the annual interest rate (in decimal form), n is the number of times that interest is compounded per year, and t is the time the money is invested for in years.
In this scenario, we have P = $7,200, r = 0.04 (4% interest), n = 4 (since the interest is compounded quarterly), and t = 3 years. Plugging these values into the formula gives us:
A = 7200(1 + 0.04/4)^(4*3)
Therefore, the amount after 3 years, A, can be calculated as:
A = 7200(1 + 0.01)^12
A = 7200(1.01)^12
A = 7200 * 1.126825
A = $8,113.14 (rounded to two decimal places)
So, Mark Welsh will have $8,113.14 in his account at the end of the 3 years.