Jonah is looking at some information for the obstacle course he is interested in completing. the x-coordinate is the number of the obstacle, while the y-coordinate is the average time to complete the obstacle, measured in minutes.

(1, 7.25), (2, 7.975), (3, 8.7725), (4, 9.64975)

jonah use an explicit formula to find the average time he will need for the 9th obstacle.

f(9) = 7.25(1.1)^9; f(9) = 17.095
f(9) = 1.1(7.25)^8; f(9) = 8396469
f(9) = 1.1(7.25)^9; f(9) = 60874407
f(9) = 7.25(1.1)^8; f(9) = 15.541