According to the U.S. Bureau of the Census, 75% of adults regularly drank alcohol in 1985. An investigator predicts that fewer adults drink now than drank then. A sample of 100 adults is asked about their current drinking habits; 67 report drinking, and 33 report not drinking. a) What is X2obt? b) What is (are) the df for this test? c) What is X2cv? d) What conclusion should be drawn from these results?