1. More on statistical versus practical signi?cance. A study with 14 subjects reported a result that failed to achieve statistical signi?cance at the 5% level. The P-value was 0.052. Write a short summary of how you would interpret these ?ndings.
2. Vitamin C and colds. In a study to investigate whether vitamin C will prevent colds, 400 subjects are assigned at random to one of two groups. The experimental group takes a vitamin C tablet daily, while the control group takes a placebo. At the end of the experiment, the researchers calculate the difference between the percents of subjects in the two groups who were free of colds. This difference is statistically signi?cant (P = 0.03) in favor of the vitamin C group. Can we conclude that vitamin C has a strong effect in preventing colds? Explain your answer.