Varieties of Normal Distribution Simulation 1.3 2003/05/29 2003/07/14 16:08:29.009 GMT-5 David Lane lane@rice.edu David Lane lane@rice.edu Matthew Jeanes mjeanes@rice.edu

General Instructions This demonstration allows you to change the mean and standard deviation of two normal distributions and observe the effects on the shapes of the distributions.When the demonstration begins, the red distribution has a mean of 50 and a standard deviaton of 10. The blue distribution has a mean of 50 and a standard deviation of 5. Notice how much more spread out the red distribution is than the blue distribution. Choose different values for the two distributions and investigate their effects.

Step by Step Instructions Show Questions Change the mean of the blue distribution to 60 and notice what happens. Did its shape change, or just its position along the X-axis? Compare the blue and red distributions. Do the areas under the curve appear to differ? They should be the same: the red distribution is wider but not as high as the blue distribution. Experiment by changing the means and standard deviations of both distributions to explore the variety of shapes a normal distribution can take on. Note that some values will not allow the distributions to be displayed in full.

Summary Normal distributions have different means and standard deviations. Normal distributions that differ only in their means have the same shape. Normal distributions with different standard deviations are more or less spread out.