dare Using a national random sample from the NEXT Generation Health Study researchers compared alcohol and drug impaired driving between high school seniors with those one year post high school The sample included 2407 high school seniors and 2178 subjects one year post high school All sub jects in the study completed a questionnaire that in cluded several questions related to recent alcohol and drug use with the following table reporting the inci dence of several of these behaviors for the two groups Binge drinking refers to at least four for females or five for males drinks within two hours 23 Explain why it is not correct to use a chi square test on this table to compare the high school seniors and post high school graduate groups Alcohol drinking at least once last 30 days Binge drinking at least once last 30 days Used marijuana at least once last year Used illicit drugs other than marijuana at least once last year High School Post High School Seniors Graduates 787 402 583 157 1044 583 654 162