Lars wants to know if warming up will runners sprint faster. twenty-four track and field athletes volunteered to participate in his study. he randomly assigns 12 athletes to warm-up for 10 minutes. all 24 participants sprint the same distance. he calculates the mean for each group and determines that the mean for the warm-up group was 7.8 seconds and the mean for the other group was 9.8 seconds. to test the difference of means, he re-randomized the data 54 times, and the differences are plotted in the dot plot below. what can lars conclude from her study?

the difference in the means is significant because a difference of 2 is very likely.
the difference in the means is significant because a difference of 2 is not very likely.
the difference in the means is not significant because a difference of 2 is not very likely.
the difference in the means is not significant because a difference of 2 is very likely.