Applet – Statistical Significance

This interactive applet for populations means illustrates the process of hypothesis testing and is part of the online content for Introduction to the Practice of Statistics, 8th Edition (Moore and McCabe).

For this discussion, we suggest you specify the hypotheses and the true population mean μ (mu), use the New Sample button to create a random sample from the population and display the sample mean from this one sample.

Repeat this process to get an idea of how often you get the wrong answer.

Try this both when Ho is true (to illustrate a Type I error) and when alternatives are true (to illustrate a Type II error).

If when you load the page, the picture does not look the same as those below, you may need to close your browser and reopen the page. We have had this problem when working with this tool in Firefox.

In the section, we provide two examples of using a similar applet. In both cases we consider IQ scores. Our null hypothesis is that the true mean is 100. Assume the standard deviation is 16 and we will specify a significance level of 5%.

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This document is linked from Errors and Power.