Example 32

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EXAMPLE 32Expressing areas under the standard normal curve as probabilities

Re-express the following areas as probabilities:

In Example 29, we found the area under the standard normal curve to the right of $Z = - 1.25$ to be 0.8944.
In Example 30, we found the area under the standard normal curve between $Z = - 1$ and $Z = 1$ to be 0.6826.

Solution

The probability that $Z$ is greater than − 1.25 is 0.8944. That is, $P (Z > - 1.25) = 0.8944$ .
The probability that $Z$ is between − 1 and 1 is 0.6826. That is, $P (- 1 < Z < 1) = 0.6826$ .

NOW YOU CAN DO

Exercises 59–70.