Question

A researcher investigates whether there is a relationship between the number of cigarettes a person smokes and whether the person wears a seat belt when driving. His thinking is that people who smoke more are less concerned about their health and safety and therefore may be less inclined to wear seat belts. He collects the following data:

Number of Cigarettes Smoked per Day

                                                0          1-14        15-34            35 and over

            ----------------------------------------------------------------------------

            Wear seat belts            175        20           42                 41

            Don’t wear seat belts  150        17           53                 64

At a 0.01 significance level test the claim that there is a relationship between the number of cigarettes a person smokes and whether the person wears a seat belt when driving.

Answer 1

The test procedure used in this problem is known as the Chi Square Test for Independence of two attributes.