Question

A researcher would like to determine whether an over-the-counter cold medication has an effect on mental alertness. A sample of n = 16 participants is obtained and each person is given a standard dose of the medication one hour before being tested in a driving simulation task. For the general population, scores on the simulation task are normally distributed with a μ = 60 a n d σ = 8 . The individuals in the sample had an average score of M = 56.5.

a. Can the researcher conclude that scores on the driving simulation task are significantly different after taking the medication? Use a two-tailed test with an α = .05 .

b. Can the researcher conclude that scores on the driving simulation task are significantly lower after taking the medication? Use a one-tailed test with α = .05 .

c. Compute Cohen's d to measure the size of the effect.

Answer 1