Researchers Are Interested in Investigating the Effect of a Drug

Multiple Choice

Researchers are interested in investigating the effect of a drug that is to be used in the treatment of patients who have glaucoma (an eye disorder associated with high eye pressure) . The goal of the drug is to reduce eye pressure. In a volunteer sample of 35 patients with glaucoma in both eyes, one eye of each patient was randomly assigned to this drug, and the other eye was given a placebo. After one week, the eye pressure was measured on each eye. The difference in eye pressure between the two eyes (drug - placebo) was measured for each patient. The sample mean difference in eye pressure was -1.21 mmHg (millimeters of mercury) , and the sample standard deviation of the differences was 4.67 mmHg.
-Are theory-based methods valid for use on this data set? Assume that the distribution of differences in eye pressure is not strongly skewed.

A) No, since the sample size is too small.
B) Yes, since the distribution of differences in eye pressure is not strongly skewed.
C) Yes, since 35 is larger than 20 and the distribution of differences in eye pressure is not strongly skewed.
D) Yes, since 35 is larger than 20.