 Centres
This applet lets you play around with data to see how the
mean and median respond.

 Growing histograms
This applet lets you watch as data are sampled from the Normal
distribution. Large samples give a good impression of the shape of the
distribution, while small samples illustrate sampletosample
variation. You can explore the effect of changing the parameters of the
normal distribution, and experiment with how many bins are appropriate
for different sample sizes.

 Linear regression
Here, you can add and relocate XY datapoints and see how the least
squares regression line changes to fit them. The correlation in your
data is displayed, and the equation of the line. If you wish, you can
add confidence limits around the line.

 Discrete probability distributions
The normal distribution is a good approximation to the Binomial and
Poisson distributions  sometimes. This applet lets you experiment to
find out when. Your choice of discrete distribution is displayed
together with the best normal approximation, and you can select numeric
intervals to see how the exact and approximate probabilities compare.
