Question

A population of bacteria is initially 2,000. After three hours the population is 1,000.

Answer 1

The population starts at 2000, so a=2000.

We also know that the population in 3 hours is 1000, so we can setup the equation:

     2000 b^3 = 1000

This gets us:

    b^3 = 1/2

And taking the cube root of both sides gives us:

    b ≈ 0.7937005259841

Rounding that to 4 places, we have:

    f(t) = 2000 (0.7937)^t