You plan to save $600 a month for the next 30 years for retirement. what interest rate would you need to have $1,000,000 at retirement? need to solve for interest rate paying into an annuity using formula p = +r/k)^(nk) -1)/(r/k)) p = payout amount (1,000,000) d = monthly deposit (600) r = interest rate (unknown) k = number of times per year interest is compounded (assumed to be the same as the deposit frequency = 12) n = number of years (30) post steps for this. this is the last question on a set of math homework and i've been able to find no useful info on how to solve this.