A Researcher Wants to Know If a New Type of Exercise

Multiple Choice

A researcher wants to know if a new type of exercise improves peoples' health. Would this be a one-tailed or two-tailed test and why?

A) One-tailed because the study is only interested in whether the exercise increases health
B) One-tailed because the study only looks at the effects of exercise and does not take other factors into account
C) Two-tailed because they will have to study healthy and unhealthy people
D) Two-tailed because there is no predicted direction of difference