Grady Zweck ski age $25$ just graduated from college excepted his first job with $47,000$ salary and is already looking forward to his retirement in $40$ years he assumes a $3\mathrm{.}8\%$ inflation rate and plan to live in retirement for $20$ years he does not want to plan on any Social Security benefits assume Grady can earn a $6\%$ rate of return on his investments prior to retirement and a $7\%$ rate of return on his investment post retirement to answer the following questions using the financial calculator a Grady wants to replace $90\%$ of his current net income with what is his annual need and today's dollars be Grady thinks he might have an average tax rate of $13\%$ retirement if he is married adjusting for taxes how much does Grady need per year and today's dollars see adjusting for inflation how much does Grady need per year in future dollars when he begins retirement in $40$ years D if he needs this amount for $20$ years how much does he need in the total for retirement E how