In the article , Attitudes About Marijuana and Political Views ( Psychological Select one answer* Reports , 1973 ), researchers reported on the use of cannabis by liberals and* 10 points Conservatives during the 1970's . To test the claim ( at 1% significance ) that the proportion of voters who smoked cannabis frequently was lower among conservatives , the hypotheses were HO : PI - P2 = 0 ( P 1 = P 2 ) Ha: PI - P,