A young executive deposits $400 at the end of each month for 7 years and then increases the deposits. If the account earns 7.2%, compounded monthly, how much (to the nearest dollar) should each new deposit be in order to have a total of $400,000 after 25 years

1 answer

Accumulated value after 7*12=84th payment
400((1+0.006)^84-1)/0.006=43522.55653
This amount after 25 years-->158445
Let P new payments then
400000-158445=P*((1+0.006)^216-1)/0.006

241555=P*440.087
P=$549