Nine months ago, Muriel agreed to pay Aisha $$1,400$ and $$800$ on dates $6$ and $12$ months, respectively, from the date of the agreement. With each payment Muriel agreed to pay interest at the rate of $7\%$ from the date of the agreement. Muriel failed to make the first payment and now wishes to settle her obligations with a single payment four months from now.

What payment should Aisha be willing to accept if money can earn $51/2\%?($Do not round intermediate calculations and round your final answer to $2$ decimal places.$)$