Chapter 14, Problem 11E

Exercises 11 and 12 refer to Chapman's correction. Chapman's correction is a small tweak on the formula used in the capture-recapture method. Using the same three input variables $n_1$ (size of the first sample), $n_2$ (size of the second sample), and k (number of tagged individuals in the second sample), Chapman's correction is given by the formula $\frac{k+1}{n_2+1}\approx \frac{n_1+1}{N+1}$. Solving for N gives Chapman's correction estimate for the size of the population.

Use Chapman’s correction to estimate the population of gray whales described in Exercise 9. Compare the two answers.