Carter wants to know if warming up will help runners sprint faster. Thirty track and field athletes volunteered to participate in his study. He randomly assigns 15 athletes to warm-up for 10 minutes. All 30 participants sprint the same distance. She calculates the mean for each group and determines that the mean for the warm-up group was 10.7 seconds and the mean for the other group was 11.7 seconds. To test the difference of means, he re-randomized the data 220 times and the differences are plotted in the dot plot below. What can Carter conclude from his study?

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