Game wardens use experiments to help determine the number of deer in the state of North Carolina. Suppose 120 deer are caught, tagged, and released back into the wild. A month later, 800 deer are caught with 16 found to have tags. Using this information, estimate the number of deer in North Carolina.

There are about 6000 deer in North Carolina.

We set up a proportion to solve this:
16/800 = 120/x

This is because 16 out of the 800 caught are tagged; there were 120 total deer tagged out of an unknown total number of deer.

Cross multiply, and we have:
16*x = 800(120)
16x = 96000

Divide both sides by 16:
16x/16 = 96000/16
x = 6000