Step-by-step explanation:
You borrow $250,000 that charges 4.8% (0.048) interest compound monthly.
$250,000 times (4.8%) 0.048 = $12,000. 250k+12k=262k. And you will make payments $1,700 monthly.
You would pay it back at around 152 months, but considering that it's a 4.8% interest, it would add on. So, the monthly interest to pay back should be higher.