1. The gas mileage of cars more than 20 years old is a normally distributed data set with a mean of 23.04 miles per gallon and a standard deviation of 3.31.

2. A data set is found to be normally distributed with a mean of 15.67 and a standard deviation of 6.21.

3. What is the area under the normal curve below the z-z-score of 1?

4. A researcher counted the hours a brand of batteries could power different devices. The data are normally distributed with a mean of 74.6 hours and a standard deviation of 9.1 hours.

What percentage of devices ran on the batteries for fewer than 63 hours?

5. A researcher counted the number of Saturday calls to emergency dispatch for a year. The data set is normally distributed with a mean of 64 and a standard deviation of 6.

What percentage of Saturdays had at least 72 calls to emergency dispatch?

6. A researcher collected the wait times at the Department of Motor Vehicles for 5 days. The data are normally distributed with a mean of 73 minutes and a standard deviation of 15.6minutes.

What percentage of patrons had a wait time between 45 and 60 minutes?