Answer:
- annually: $19,037.37
- quarterly: $19,602.30
- monthly: $19,736.29
- continuously: $19,804.52
Explanation:
The amount of an investment P compounded n times per year at annual rate r for t years is ...
A = P(1 +r/n)^(nt)
This formula is conveniently evaluated by a calculator or spreadsheet. In the attached, we made a version of it that only depends on the value of n, the number of compoundings per year. That is used to compute the numbers shown in the attachment, and copied to the Answer block above.
__
Continuously compounded interest results in an account balance computed using the formula ...
A = Pe^(rt) . . . . where the variables have the same definitions as above.
For P=7000, r=0.08, t=13 years, the continuously-compounded account will have a balance of ...
A = 7000e^(0.08·13) = 7000e^1.04 ≈ 19,804.52 . . . . dollars