The data set "DosPrepost" contains depression diagnosis of patients at baseline (pretreatment) and one year after treatment (posttreatment) in the DOS. We are interested in whether there is any change in depression rates between pre- and post treatment.

(a) Carry out the two-sided asymptotic and exact tests and summarize your results.

(b) Carry out the two one-sided exact tests and summarize your results. Please write down the alternatives and the procedure you use to obtain the p-value.