6. Chimptastic disease is a hereditary condition that makes you think that you are Neoplean Bonaparte, causes you to lose the ability to speak in complete sentences, or to swallow pretzels. In an eort to cure this ailment, 98 twin pairs were recruited into a clinical trial. For each twin pair, one member was randomly assigned to an experimental drug treatment while the opposite member was assigned to a placebo. The disease was deemed to be cured if a patient showed no symptoms after 6 months of treatment.

(a) Is this a prospective study or a retrospective study?

(b) Which of the following procedures is most appropriate for testing the null hypothesis that the drug treatment has no eect on whether or not the disease is cured?

One-Sample t-test

Paired t-test

Chi-Square Test for Independence

Two-Sample t-test

McNemaris Test