This exercise illustrates the relationship between statistical power (the probability of rejecting a false null hypothesis) and four features of the test situation: the size of the difference between...

This applet performs a hypothesis test for the mean of a single normal population, variance known. Users set the hypothesized mean, true mean, variance, and appropriate alternative hypothesis. The...

This webpage uses the criminal trials in the US Justice system to illustrate hypothesis testing, type I error, and type II error. An applet allows the user to examine the probability of type I errors...

This applet demonstrates the concept of power. Users select the hypothesized mean, the alternative mean, the sample size, and the number of samples. The applet shows the hypothesized histogram and...

These four applets demonstrate effects on the power curve for the difference in means, the difference in proportions, the mean change, and the correlation coefficient. Each applet allows users to...

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