Data by Mazze et.al(1971) deal with the preoperative and postoperative creatinine clearance (ml/min) of six patients anaesthetized by halothane

PATIENT

1 2 3 4 5 6

Preoperative 110 101 61 73 143 118

Postoperative 149 105 162 93 143 100

i) Why is the paired t-test preferable to the two-sample t-test in this case (1mks)

ii)Carry out the paired t-test and test the significance of the difference (3mks)

iii) what is the model for your analysis (1mks)

iv) Set up a 99% confidence interval on the difference (3mks)