Please provide an explanation of all answers included which formulas you used.

1Your grandmother invested one lump sum 17 years ago at 4.25 percent interest. Today, she gave you the proceeds of that investment which totaled $5,539.92. How much did your grandmother originally invest? Round to the nearest cent. Do not include any unit (i.e. $, %, etc.)

2 Your grandparents are talking about their retirement in a year. They told you that they should have enough in their retirement funds to pull $50,000 a year for 20 years, starting one year from today. If the discount rate is 5 percent, how much should they have in their retirement account now? Round to the nearest cent. Do not include any unit (If your answer is $111.11, then type 111.11 without $ sign.)

3You purchased Honda Civic for $18,290 today. You took an auto loan at the annual interest rate of 3.65%. You are going to make equal monthly payment for next 6 years starting a month from now. How much is your monthly car payment? Round to the nearest cent. Do not include any unit (If your answer is $111.11, then type 111.11 without $ sign.)