Joe bob wants to buy a car and will need to take out a loan in order to make the purchase. His current monthly income is 3,500 per month. His mortgage payment is 900 per month, and his student loan...

Joe bob wants to buy a car and will need to take out a loan in order to make the purchase. His current monthly income is 3,500 per month. His mortgage payment is 900 per month, and his student loan payment is 350 per month

according to the affordability formulas given can he afford to take out another loan?
when should he follow the affordability formulas? In what case should he not?
how could taking out the car loan impact his other priorities?

what is the affordability formula I need to use as well