Yuko $($age $45$ at year$-$end$)$ has been contributing to a tradtiinal IRA for years $($all deductible contributions$),$ and her IRA is now worth $$50,000.$ She is trying to decidebwhetherbshe should convert her traditional IRA into a Roth IRA $.$ Her current marginal tax rate is $24$ percent. She plans to withdraw the entire balance of the account in $20$ years $,$ and she expects to earn s before tax rate of return of $5$ percent on her retirement accounts and a $4$ percent after tax rate of return on all investments outside of her retirement accounts $.$ For each of the following alternative scenarios $,$ indicate how much more or less Yuko will accumulate after taxes in $20$ years if she converts her traditional IRA into a Roth IRA $.$ Be sure to include the opportunity cost of having to pay taxes on the conversion. B$)$ when she withdraws the retirement funds in $20$ years, she expectsbher marginalnrate to be $18$ percent.