Suppose John graduated on his $22$

nd birthday and he also started his first job on that day. His

initial salary is $$48,000$ per annum $($i$.$e$.,$ $$4,000$ at the end of the first month$).$ He is paid at the

end of every month. He has signed up to deposit $3\%$ of his after$-$tax salary into a retirement

scheme upon which no further tax is due. His employer contributes nothing. His tax rate is

$22\%.$ He expects his retirement investments to grow at an APR of $9\%$ per annum with monthly

compounding after all fees. He expects that he will get a raise at an APR of $3\%$ per annum with

monthly compounding $($i$.$e$.,$ his salary goes up a little every month$).$ He plans to work until his

final pay packet arrives on his $65$th birthday, whereupon he will retire.

$1.$ How much money John should expect to find in his retirement scheme upon his $65$th

birthday? $(30$ marks$)$

Where does this $$517$ for the $2023$ financial year come from I dont see anywhere that this number could come from?