Miranda obtains a $296,000 15/5 balloon mortgage with a rate of 6.75%. What will her monthly payments be?

The main formula for computing it, is

P=R[1 - (1+i) ^-n) ] / i

P the present value of annuity = $296,000

15/5 balloon mortgage, 15 is the number of years during which the initial interest rate applies

6.75%=6.75/100=0.0675 and i = 0.0675/12

n=12*15=180 months

(1+i) ^-n = (1+0.0675/12) ^-180=0.364

1 - (1+i) ^-n / 0.0675/12 = 1-0.364/0.0675/12=0.63/0.0675/12=112

$296,000=R x 112, finally we found R = $296,000 / 112=$2642.8

her monthly payments will be $2642.8