1. Suppose the following initial model is specified for assessing the effect of type of hospital (HT), considered as the exposure variable, on the prevalence of surgical wound infection, controlling for the other four variables on the above list: logit PðXÞ ¼ a þ bHT þ g1HS þ g2CT þ g3AGE þ g4SEX þ d1HT  AGE þ d2HT  SEX: Describe how to test for the overall significance (a “chunk” test) of the interaction terms. In answering this, describe the null hypothesis, the full and reduced models, the form of the test statistic, and its distribution under the null hypothesis.