Question

Lars wants to know if warming up will help 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 10.8 seconds. To test the difference of means, he re-randomized the data 225 times and the differences are plotted in the dot plot below. What can Lars conclude from her study?

Answer 1

@Valpey @RadEn
help ill give you a medal

Answer 2

@ganeshie8 CAN U HELP ME PLEASE

Answer 3

In this case, we are comparing the observation of the test group performing 3 seconds faster on average versus a randomized distribution where we observed that level of improvement 3 out of 30 times. The observation of 3 seconds of improvement for the group who warmed up is good evidence in favor of the hypothesis that warming up improves speed.

But, that result isn't super unusual. If Lars had randomly split the group up after the running (assuming the same times were run), he would observe this phenomenon 10% of the time. Because of that we would say we have good evidence, but not so much that we would say anything definitive. Reproducing this result in a separate study would significantly improve our confidence.