Fred thought that taking lots of vitamin C would help prevent aging. He successfully recruited 2,000 healthy participants for his study. Half of the participants received vitamin C, whereas the other half received a placebo for ten years. At the end of the study, he used a reliable measure of aging. He used a t test for independent samples and found a significant difference between the two groups. The p value was 0.01 and the effect size was 0.004. What can he conclude?
