In another project, researchers caught and tagged 85 sea lions in a bay. Later they caught and released 50 sea lions. Of those, 9 had tags. Estimate the sea lion population in the bay. about 529 sea lions about 472 sea lions about 194 sea lions about 153 sea lions

The correct answer is about 472 sea lions.

We can set up a proportion to solve this. 9 lions were tagged out of a sample of 50. This gives us the ratio 9/50 for the first part of the proportion.

For the second ratio, we know 85 lions were tagged out of an unknown population; this gives us 85/x.

Our proportion is

9/50 = 85/x

Cross multiply:

9*x = 50*85

9x = 4250

Divide both sides by 9:

9x/9 = 4250/9

x = 472.222

To the nearest whole number, this is 472 sea lions.