Question

The National Highway Traffic Safety Administration published the Motor Vehicle Occupant Safety Survey in March 2000. Their survey of seat belt use asked 3569 male and 3893 female drivers, “When driving this [vehicle], how often do you wear your [lap/shoulder] belt?” In response, 74% of the male drivers and 84% of the female drivers answered “All of the time”.

1. How many of the male drivers answered “All of the time”? How many of the female drivers?

2. Estimate, with 95% confidence, the difference between the proportion of all male drivers and the proportion of all female drivers who would answer that the wear their seat belt “all of the time”. Remember to use steps A – E (Population, Statistical Method, Sample, Statistical Results, and Conclusion).

Answer 1