Linear modeling

Question

In 1991, the moose population in a park was measured to be 3800. By 1999, the population was measured again to be 3160. If the population continues to change linearly:

Find a formula for the moose population, P, in terms of tt, the years since 1990.

What does your model predict the moose population to be in 2008?

Answer 1

in 8 years moose decreased by 640

that's 640/8 = 80 loss per year

by 2008 that's 17 years or 17(80) = 1360 loss from 3800

3800-1360 = 2440 moose in 2008

1990 - 3880

1991 - 3800

1999 - 3160

2008 - 1360

P(t) = 3880 - 80t where t= years since 1990

P(18) = 3880-80(18) = 3880- 1440= 2440 in 2008, 2008-1990= 18