Erica wants to know if warming up will help runners sprint faster. Twenty track and field athletes volunteered to participate in her study. She randomly assigns 10 athletes to warm-up for 10 minutes. All 20 participants sprint the same distance. She calculates the mean for each group and determines that the mean for the warm-up group was 10.9 seconds and the mean for the other group was 11.9 seconds. To test the difference of means, she re-randomized the data 200 times and the differences are plotted in the dot plot below. What can Erica conclude from her study?

A:The difference in the mean

Question

Erica wants to know if warming up will help runners sprint faster. Twenty track and field athletes volunteered to participate in her study. She randomly assigns 10 athletes to warm-up for 10 minutes. All 20 participants sprint the same distance. She calculates the mean for each group and determines that the mean for the warm-up group was 10.9 seconds and the mean for the other group was 11.9 seconds. To test the difference of means, she re-randomized the data 200 times and the differences are plotted in the dot plot below. What can Erica conclude from her study?

A:The difference in the mean