Answer:
It must be invested at 19% per year.
Explanation:
Given that Tanner is entering high school and needs to save as much money as he can for college, to determine what rate of return must Tanner earn for his investment of $ 5,000 to double in 4 years, the following calculation must be performed:
72 / X = 4
72/4 = X
18 = X
Thus, approximately, it must be invested at 18% per year. But it must be checked by the following calculation:
5000 x 1.18 ^ 4 = 9,693.88
5000 x 1.19 ^ 4 = 10,026.69
Thus, it must be invested at 19% per year.
