The function f(x) = 200(0.901), where x is the time in
years, models a declining lemming population. how
many lemmings will there be in 7 years?

There will be 96 lemmings in 7 years

Step-by-step explanation:

we have

This is a exponential function

where

x ------> the time in years

f(x) ----> lemming population

so

For x=7 years

substitute in the function

There will be 96 lemmings in 7 years

i think the amount would be $140.62