Have each team calculate the estimated population and the upper and lower confidence intervals. Graph high, estimated and low population estimates of all teams on a scatter plot. Tell students the total population and draw a horizontal line from that number on the y axis, extending to the end of the x axis. For a population of 100 fish with 50 marks, the sample size should be about 20 fish. Fish can be marked before the activity or a team can do it.
Extensions Have students determine correct sample size.
Estimate high and low using different confident intervals. Calculate variance of estimated population sizes. Create a modified box plot of data series. Calculate the volume of water in the pool and the population density. Determine length distribution of captured fish.