Suppose we obtain a random sample of 80 Champaign voters, of which 55 support marijuana legalization. We also obtain a random sample of 100 Urbana voters, of which 75 support marijuana legalization. Let pC be the true proportion of Champaign voters who support marijuana legalization and let pU be the true proportion of Urbana voters who support marijuana legalization.
(a) Calculate the p-value for the test H0: pU=pC versus H1: pU≠pC.