Aconcession stand vendor counts the money in the register. after 2 h it has $82.75. after 6 h is has $ 360.75. how much money will be in the register at the end of an 8h shift?
a.480.00
b.489.25
c.499.75
d.500.00

I believe the answer would be c. $499.75. If you take (360.75-82.75)/(6-2) you get 278/4 which is dollars/hour, and that =69.5 so the rate of increase is $69.50 per hour, therefore if 6 hours produced $360.75 then you +$69.50•2(hours) and get $499.75