Jonathan, a $24$ year old college graduate just started a new job and is enrolling in the

company$$s $401($k$)$ plan. He has set the goal to retire at age $55$ and wants to know

how much he should contribute each semi$-$monthly paycheck. His new employer

matches his retirement contribution dollar for dollar with no maximum. He told you

he would like to have a retirement income of $$50,000$ per year after tax in today$$s

dollars. Assume a life expectancy of age $95,$ inflation rate of $3\mathrm{.}5\%,$ average income

tax rate of $20\%$ and an annual rate of return of $10\%.$ If Jonathon makes $$75,000$

annually and expects his income to remain level, what percentage of his salary

should he enter on the enrollment form $($Round off to nearest $(1)/(2)\%)?$