Probability and Statistics > Probability > Normal Probability Practice Problems

These normal probability practice problems will help you practice calculating z-scores and using the z-table.

General steps for solving normal probability practice problems:

- Use the equation above to find a z-score. If you don’t know how to look up z-scores (or if you want more practice, see this z-score article for videos and step-by-step instructions.
- Look up the z-score in the z-table and find the area.
- Convert the area to a percentage.

If you more need help with these steps, see the normal distribution word problems index, which outlines the steps in detail (with videos).

## Normal Probability Practice Problems.

**Click on the question for the answer!**

**3. IQ scores have a normal distribution with a mean of 100 and a standard deviation of 15. What percent of people have an IQ above 120?**

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*Statistical concepts explained visually* - Includes many concepts such as sample size, hypothesis tests, or logistic regression, explained by Stephanie Glen, founder of StatisticsHowTo.

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