Exam 11: Two-Sample Hypothesis Tests

In a random sample of 370 cars driven at low altitudes, 43 of them exceeded a standard of 10 grams of particulate pollution per gallon of fuel consumed. In an independent random sample of 80 cars Driven at high altitudes, 23 of them exceeded the standard. Can you conclude that the proportion of High-altitude vehicles exceeding the standard is greater than the proportion of low-altitude vehicles Exceeding the standard at an $\alpha = 0.05$ level of significance?

The football coach at State University wishes to determine if there is a change in offensive production between the first half and the second half of his team's recent games. The table below Shows the first-half and second-half offensive production (measured in total yards gained per half) For the past six games. State the null and alternative hypotheses.

The football coach at State University wishes to determine if there is a decrease in offensive production between the first half and the second half of his team's recent games. The table below Shows the first-half and second-half offensive production (measured in total yards gained per half) For the past six games. State a conclusion using the $\alpha = 0.02$ level of significance.