An Investigator Is Considering a Study for Assessing the Change

Multiple Choice

An investigator is considering a study for assessing the change in viral loads among those individuals who are on drug treatments versus those who are not. Two sample sizes were proposed (300 and 600) . If the investigator chooses the larger sample size, what will happen to the precision (width) of the interval estimate?

A) Width remains the same because sample size is not related to the width of the interval.
B) Width gets smaller because a larger sample reduces the margin of error.
C) Width gets larger because with a larger sample there is more variability.
D) None of the above.