Section 6.4Summary

1. Continuous random variables assume infinitely many possible values, with no gap between the values. Probability for continuous random variables consists of the area above an interval on the number line and under the distribution curve.
2. The uniform probability distribution has constant probability from its left to its right endpoints and is therefore shaped like a rectangle.
3. The normal distribution is the most important continuous probability distribution. It is symmetric about its mean and has standard deviation .
4. The standard normal distribution has mean and standard deviation . This distribution is often called the distribution. The table and technology can be used to find areas under the standard normal curve. In the table, the numbers on the outside are values of , and the numbers inside are areas to the left of values of .
5. The table and technology can also be used to find a value of , given a probability or an area under the curve.