1. Use SAS to perform EM on a real data of your choice or the example dataset given in the class. If you use the example dataset given in the class, estimate the mean and variance of MH1 and MH1 when time=1. 2. Answer the following questions: a) What is the missing-data pattern? b) Is multiple imputation like EM? c) Is multiple imputation just making up data? d) What is the difference between single imputation and multiple imputation methods? f) If the analyst's model is a special case of the imputer's one and if the the imputer's extra assumption is true, will the MI inference be valid? Will the ML estimate be more efficient than an observed data estimate derived purely from the analyst's model? Why?