Sample Size Effect On The Sample Mean Applet
How it works: Students may generate samples of different sizes and see the means of the samples plotted vs. sample size on the plot abpve. Students can see the center of the distribution does not depend on sample size, but the variability of the mean decreases as sample size increases. The mean and standard deviation of the normal distribution which the samples come from can be changed in the parameter statement. Don't forget to have students click on the graph to verify the center of the distributions.
<PARAM name=mean value="100" > - the true mean of the population
<PARAM name=sigma value="2" > - the true standard deviation of the population