Use the compound interest formulas A=P(1+r/n) ^nt and A=Pe^rt to solve the problem given. Round answers to the nearest cent. Find the accumulated value of an investment of $20,000 for 3 years at an interest rate of 6% if the money is a. compounded​ semiannually; b. compounded​ quarterly; c. compounded​ monthly; d. compounded continuously.