A Study Is Conducted to Determine the Effect of Different

Multiple Choice

A study is conducted to determine the effect of different doses of a cold medication on reaction times. In a study of 20 participants between 20 and 25 years of age, half were given a single dose of medication and the other half were given two doses. Thirty minutes after dosing, a simple mechanical experiment measured subject reaction time in milliseconds. The results are summarized below. Calculate the 95% confidence interval for the difference in reaction times for these two groups. Assume that the reaction times are normally-distributed and that the treatments were randomly assigned.

A) (-351, 12)
B) (-326, -14)
C) (-385, 46)
D) (-201, -28)