Question: In the United States approximately 900 people die in bicycle accidents each year. One study examined the record of 1711 bicyclists age 15 or older who were fatally injured in bicycle accidents between 1987 and 1991 and were tested for alcohol. Of these 542 tested positive for alcohol (blood alcohol concentration of 0.01% or higher).

a. Summarize the data with appropriate descriptive statistics.

b. To do statistical inference for these data, we think in terms of a model where p is a parameter that represents that a rider test positive for alcohol. Find a 95% confidence interval for p.

c. Test the claim that p = 0.25. Report the z value and its p-value. Is your result significant at 0.05% level? Is your result significant at 0.10%?

d. Can you conclude from your statistical analysis of this study that alcohol causes fatal bicycle accidents?