 # Statistics Lectures - 20

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".

### Statistics - Lecture 59

One Sample z-Test
1. Define Null and Alternative Hypothesis
2. State Alpha
3. State Decision Rule
4. Calculate Test Statistic
5. State Results
6. State Conclusion

### Statistics - Lecture 60

One Sample z-Test for Proportions
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

### Statistics - Lecture 61

One Sample t-Test
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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