A series of free Statistics Lectures with examples & solutions in videos.

These lectures discuss one sample z-test and one sample t-test.

This is page twenty of the series of free video lessons, "Statistics Lectures".

1. Define Null and Alternative Hypothesis

2. State Alpha

3. State Decision Rule

4. Calculate Test Statistic

5. State Results

6. State Conclusion

Example:

A survey claims that 9 out of 10 doctors recommend aspirin for their patients with headaches. To test this claim, a random sample of 100 doctors is obtained. Of these 100 doctors, 82 indicate that they recommend aspirin. Is this claim correct? Use alpha = 0.05

z-Tests are commonly done when the population standard deviation is known. t-Tests are commonly done when the population standard deviation is unknown. We use the t-distribution because the unknown population standard deviation is now a value we must estimate.

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