Lets say there is a drug that proposes to make one grow taller. A study is performed and the results state that there IS statistical difference with a Z = 3.1 p<.05. What should be stated about the magnitude of the increase in height? Should the study also have to state the magnitude of the height increase, or better yet the mean of the height before taking the drug and the mean after taking the drug? As I study statistics, it seems that the statement, "Z = 3.1 p<.05." is a requirement for a scientific report but I don't see where the population and sample means have to be stated. I hope this question makes sense.