Question: (5 marks). A study considered the effect of diet control over caries development in children. Of 30 children, 15 were randomly selected to receive controlled diet over 5 years (cases), and the other 15 formed a control group. Eight of the 15 in control group developed caries during this 5-year period, while one of the 15 children developed caries in the study group. The data are stored in the file data2_Q3.sav.

a. Should we use chi-square test or Fisher’s exact test? Why? (2 marks)

b. Use Fisher’s exact test to determine whether the results were significantly better for study group than control group. What is your result? (3 marks)