A computer can perform random sampling and estimation much more quickly than you can by hand. The following Interactive Activity is set up to do just that.
Use the Interactive Activity to obtain three more samples of 10 sub-regions and to calculate resulting estimates for the total number of penguins in the region.
This activity requires the Flash plug-in, which you can download for free from Macromedia's Web site. For those who prefer, there is a non-interactive version of this activity.