Please Help Me With This Problem

Acircle has a diameter will endpoints of (-2,8) and (6, 4). what is the center of the circle

Ricky takes out a $31,800 student loan to pay his expenses while he is in college. after graduation, he will begin making payments of $190.66 per month for the next 30 years to pay off the loan. how much more will ricky end up paying for the loan than the original value of $31,800? ricky will end up paying $ more than he borrowed to pay off the loan.

15/16 as a decimal rounded to the nearest hundredth