You have a friend that is planning to retire starting one year from today, at which time they intend to start a fixed annual withdrawal from their retirement account.

$$a$.$ How much should they have in their retirement account if they plan to withdraw $$25,000$ at the end of each year for the next $20$ years, assuming they can earn an annual return of $6\%$ after$-$tax on their portfolio?

$$b$.$ How much would they need if that could achieve a return of $8\%$ per year after$-$tax?

Needs to be completed in Excel $($see image below$)$