Question

A new drug is thought to lower cholesterol. Nine individuals were matched to nine other individuals with same age, gender and baseline cholesterol. Within each pair, one individual was assigned to the drug, and the other was assigned to placebo. Thereductions in cholesterol (unit: mg/dl) after 30 days are recorded as follows, and suppose the differences are a random sample from a normal population. Conduct an appropriate test to check if the drug is effective at significance level 0.05.

Matched Subjects	1	2	3	4	5	6	7	8	9	Mean	SD
Drug	1	5.5	1.7	0.9	2	5.5	5.1	4	5.2	3.43	2.01
Placebo	1.4	4.5	1.7	0	1.5	4.7	3.9	4.2	4.1	2.89	1.73
Difference	–0.4	1	0	0.9	0.5	0.8	1.2	–0.2	1.1	0.54	0.60

Answer 1