Tim wants to buy an apartment that costs $$750,000$ with an $85\%$ LTV mortgage. Tim got a $30$ year, $3/1$ ARM with an initial teaser rate of $3\mathrm{.}75\%.$ The reset margin on the loan is $300$ basis points above $1$ year CMT$.$ In year $4,$ the index resets to $3\mathrm{.}50\%.$ What will his new mortgage payment be in year $4?($Write the answer as a number rounded to two decimals $($e$.$g$.$ if you get $$50,66666,$ write $50\mathrm{.}67).$