Law enforcement agencies in Charlotte, NC conduct an average of 120,000 traffic stops per year. By law, the agencies collect information about all traffic stops, the reason for the stop, and the type of enforcement action taken. A random sample of 225 traffic stops revealed that 43 of the drivers were under 25 years of age. A total of 144 were issued a citation while the rest were given a verbal or written warning. A total of 30 drivers were under 25 years of age and issued a citation.
Use this information to complete the contingency table below.
Age Citation Warning Total
Under 25
25 or older
Total
2. What type of study is this?
a. Experiment
b. Observational Study
3. Compute the difference in the proportions of drivers who received a citation in the two groups:
a. p^under25
b. p^over25
Round your result to three decimal places.
4. Insurance rates are usually higher for drivers under the age of 25. Which set of hypotheses would we use to test whether this was justified?