Answer: 17873.75 dollars
Step-by-step explanation:
We can use the equation: l = p x r x t (Total Interest = principal x interest rate x years/time)
9050 will be the principal; it's the amount you deposit in the first place.
7.5% is the interest rate. You can convert it to 0.075 as a decimal.
13 is the years/time. If Marcus's parents put the college fund in when he was 5 and now he's 18, there has been 13 years in between.
9050 x 0.075 x 13 = 8823.75
8823.75 + 9050 = $17873.75
So in Conclusion, the total amount in the account when Marcus is 18 is 17873.75 dollars.
Hope this helps!