Amy has a student loan of $$50,000,$ which spans a $20-$year term. If she aims to pay off half of the loan principal within the next $8$ years, considering an interest rate of $6\mathrm{.}00\%$ with monthly compounding, please calculate the monthly payment $($PMT$)$ she needs to make using excel PMT$()$ function.

$$860\mathrm{.}61$

$$328\mathrm{.}54$

$$453\mathrm{.}54$

$$5525\mathrm{.}90$