P = (PMT [((1 + 〖r)〗^n- 1) / r]) (1 + r)
P = ($50,000 [((1 + 〖0.06)〗^5 - 1) / .06]) (1 + .06)
P = $298,765.90
As another example, what if the interest on the investment compounded monthly instead of annually, and the amount invested were $4,000 at the end of each month? The calculation is:
P = ($4,000 [((1 + 〖0.005)〗^60- 1) / .06])(1 + .005)
P = $280,475.50
The .005 interest rate used in the last example is 1/12th of the full 6% annual interest rate.