Question

Certain states require your vehicle to be inspected for safety on a yearly basis. Police randomly stop drivers from time to time to ensure that the car's safety inspection is up to date. Last year, an average of 10% of cars stopped were ticketed for having expired stickers. The state then funded a marketing campaign to increase awareness of the safety inspection requirement in hopes of lowering the amount of tickets issued. Last month the police issued tickets for expired inspections to 43 of 628 cars they stopped. Is this evidence to suggest that the marketing campaign was effective? Assume all conditions have been met.

Part 1 of 3: 2 pts

State the null and alternative hypotheses in symbols and words. Use the editor! Assume conditions have been met.

Part 2 of 3: 6 pts

Perform the appropriate hypothesis test "by hand" using the equation editor. Assume an alpha level of 0.05 for your test. Be sure to use the appropriate probability notation. Then find the corresponding confidence interval for the proportion of cars whose safety inspections have expired. Use α=0.05.

Part 3 of 3: 2 pts

State your conclusion making sure to site whether we reject or fail to reject and what that means in context. Then support your conclusion with the results from your confidence interval. Be sure to note whether the hypothesized value falls in our interval and what that means.

Answer 1