a) Define an arithmetic annuity immediate with n payments. b) Give the formula for the future value of an arithmetic annuity due with n payments starting at $1 and increasing by $1 each period if the effective interest rate per period is r. Satoshi is saving for retirement. At the end of the first year he deposits $6000. Each year after that he deposits $500 more than the year before. The interest rate is 4% compounded semi-annually. c) How much money has he saved after 20 years? d) How many more years until he has saved at least twice as much as your answer from part c)?) a) Define an arithmetic annuity immediate with n payments. b) Give the formula for the future value of an arithmetic annuity due with n payments starting at $1 and increasing by $1 each period if the effective interest rate per period is r. Satoshi is saving for retirement. At the end of the first year he deposits $6000. Each year after that he deposits $500 more than the year before. The interest rate is 4% compounded semi-annually. c) How much money has he saved after 20 years? d) How many more years until he has saved at least twice as much as your answer from part c)?)