This applet will allow you to explore the idea of using a z test to test a simple null hypothesis. You can change the sample mean, the mean under the null hypothesis, the standard deviation, the sample size, or z itself, and examine the areas under the curve. When you change any value you must press the Enter (or Return) key to have that value take effect.
- At the bottom of the display you can choose a one- or a two-tailed test, or you can calculate the cumulative probability from the lower end of the distribution (really the lower one-tailed probability), or the probability between the two cutoffs of a two-tailed test.
- Next change the entry for YMean, which in our case is the individual observation. How does this affect the significance level of the test?
- What happens to the signficance level as you slowly decrease the size of the standard deviation? Does this make sense?
- Enter the values from Section 8.10.
Comments to: Gary.McClelland@Colorado.edu
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