CAPTURE-RECAPTURE STUDY

Question

In a capture-recapture study, a biologist tagged and released 310 deer. A moth later she captured 40 deer, 30 of which had tags. About how many deer were in the population?

Answer 1

Let x = the population:

310/x = 30/40

Cross multiply to solve for x. Round to the nearest whole number, because you can't have part of a deer.