A two-arm randomized trial will be conducted to investigate the effectiveness of a new treatment designed to decrease cholesterol for people with hypercholesterolemia. The study will randomly assign participants to receive either the new treatment or the standard care. Based on its past use, the standard care treatment effectively reduces cholesterol 80% of the time.

What sample size is needed per group to detect an increase of effectiveness under the new treatment of 10% with a 95% confidence level ( = 0.05) and 90% power.