4. Marijuana and Road Safety Gallup polled 635 Democrats and 372 Republicans on their opinion of driving while impaired by marijuana. 20% of Democrats and 35% of Republicans said that driving while impaired by marijuana poses a very serious threat, compared to alcohol, prescription painkillers, and prescription antidepressants. (a) Suppose we want to conduct a hypothesis test for evaluating whether the proportions of Democrats and Republicans who think that driving while impaired by marijuana poses a very serious threat are different. i. Calculate the sample statistic for this hypothesis test. ii. Calculate the standard error for this hypothesis test. iii. Perform the test and state your conclusion, use a = 0.05. (b) Suppose we want to estimate the difference between the proportions of Democrats and Republicans who think that driving while impaired by marijuana poses a very serious threat using a confidence interval. No calculation is required for the following questions. i. Is the value of the sample statistic for this confidence interval different than the sample statistic for the hypothesis test in part (a)? If yes, explain how and why. ii. Is the value of the standard error for this confidence interval different than the standard error for the hypothesis test in part (a)? If yes, explain how and why. iii. Construct and interpret a 95% confidence interval