Monday, July 20, 2009

statistics - standard normal curve


This sketch can be used to discuss various aspects of the normal curve. Normal curves have a specific nature to them that is brilliantly captured by Sketchpad. Every combination of Mean (mu) and Standard Deviation (sigma) yields a graph with the same area, and this sketch provides a look at the changes that take place in order to satisfy such a constraint. The calculations of area were made using trapezoidal estimates and summed iteratively as described in Sketchpad's sample calculus sketches. There are four pages: Normal Distribution with sliders, Standard Normal Distribution with z-scores, Confidence Intervals, and Standard Normal Distribution with a calculation of the shaded region corresponding to P( a < Z < b ).

Keywords: normal distribution, normal curve, N(0,1), mu, sigma, mean, standard deviation, z-score, probability, density curve, standardize, standard normal, normal random variable, confidence interval, CI, z*, statistics


  1. These are masterful gsp's. Thanks so much for sharing them.

  2. Really helpful thanks a lot=)
    Simon Kong from Malaysia..