A simple random sample of front-seat occupants involved in car crashes is obtained. Among

2777 occupants not wearing seat belts, 30 were killed. Among 7779 occupants wearing seat belts, 18 were killed. Use a 0.01 significance level to test the claim that seat belts are effective in reducing fatalities. Complete parts (a) through (c) below.

a.Identify the test statistic.

Identify the P-value.

What is the conclusion based on the hypothesis test?

b. Test the claim by constructing an appropriate confidence interval.

What is the conclusion based on the confidence interval?

c. What do the results suggest about the effectiveness of seat belts?