Answer Happy

Class Activity 15D Using Random Samples to Estimate Population Size by Marking (Capture-Recapture) You will need a bag filled with a large number (at least 100) of small, identical beans or other small objects that can be marked (such as small paper strips or beads that can be colored with a marker). Pretend that the beans are fish in a lake. You will estimate the number of fish in the lake without count- ing them all by using a method called capture-recapture. 1. Go "fishing:" Pick between 20 and 50 "fish" out of your bag. Count the number of fish you caught, and label each fish with a distinctive mark. Then throw your fish back in the lake (the bag) and mix them thoroughly. 2. Go fishing again: Randomly pick about 50 fish out of your bag. Count the total number of fish you caught this time, and count how many of the fish are marked. 3. Use your counts from parts 1 and 2 to estimate the number of fish in your bag. Explain your reasoning.