A concession 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