(Compound interest) To what amount will the following investments accumulate? a. $4,900 invested for 8 years at 9 percent compounded annually b. $8,100 invested for 8 years at 9 percent compounded annually c. $750 invested for 12 years at 11 percent compounded annually d. $23,000 invested for 4 years at 6 percent compounded annually a. To what amount will $4,900 invested for 8 years at 9 percent compounded annually accumulate? (Round to the nearest cent.) b. To what amount will $8,100 invested for 8 years at 9 percent compounded annually accumulate? (Round to the nearest cent.)