Phase I clinical trails are run to determine the safely of all new drugs, especially with respect to the severily and duration of side effects. A physician is overseeing a phase I trial based on 8000 heathly participants. Half of the participants are given the drug, and half are given an inert pill. The mean duration of side effects for those participants who were given the drug was 72 hours with a margin of error of 6 hours. The physician is planning to replicate the trial in an attempt to decrease this margin of error. Which of the following will most likely lead to a decrease in the margin of error for the mean duration of side effects?

Options

A. Decrease the trial size to 400 heathly participants
B. Decrease the trial size to 400 participants and replace half the healthy participants with sick patients
C. Increase the trial size to 1,600 healthy participans
D. Increase the trial size to 1,600 participants, and replace half the healthy participants with sick patients.

Answer

C

Explanation

Difficult: Easy
Category: Problem Solving and Data Analysis/ Statistics and Probability.
Strategic Advice: Margin of error is a measure of data consistency. Think about how could alter the sample pool for a study to decrease the margin of error. ltbr. Getting to the Answer: When conducting trials (or surveys), larger sample sizes lead to more reliable data. This, in trun, results in smaller margins of error. Therefore, the physician should increase the number of participants in the trial. Eliminate A and B. Replacing half the healthy participants with sick patients introduces another variable into the trial: consequently, doing this will prevent a valid comparision of the margins of error of the two trials. Choice (C) must be correct.