A pharmaceutical company conducted a randomized controlled trial to determine the efficacy of a new topical solution for hair growth in men with male pattern baldness. Researchers decided hair count must increase by at least 20% more in the drug group than the placebo group to be clinically meaningful. They selected a sample size giving the statistical test 80% power to detect this difference at the 5% significance level. The trial found a significant difference in average hair count between the groups.

1. No guesses please! A pharmaceutical company conducts a randomized controlled trial to
determine the efficacy of a newly developed topical solution for inducing hair growth in men
with male pattern baldness. Company researchers decide that average hair count must increase
by at least 20% in the drug-treated group, compared to the placebo group, to be considered a
clinically meaningful difference. They select a sample size that will ensure 80% power for the
statistical test, and carry out this test at the 5% level of significance. The investigators report a
significant difference in average hair count between the groups (p
Solution
A is the answer