Teen smoking II Suppose that, as reported by the Centers for Disease Control, about 18% of high school students smoke tobacco. You randomly select 120 high school students to survey them on their attitudes toward scenes of smoking in the movies.

1. What’s the expected number of smokers?

2. What’s the standard deviation of the number of smokers?

3. The number of smokers among 120 randomly selected students will vary from group to group. Explain why that number can be described with a Normal model.

4. Using the 68–95–99.7 Rule, create and interpret a model for the number of smokers among your group of 120 students.