Question: (3 marks). A study identified 47 patients in need of two fillings. Subjects were then treated with one filling using material A and the other filling with material B. In order to compare the success rate between material A and B over two years, the data are collected and stored in the file data2_Q4.sav and shown in the contingency table below.

a. Use McNemar’s test to determine if the proportion of success with material A is the same as material B in this matched-pairs study. Comment on your results. (3 marks)