.Sam wants to know if coffee will help students perform better on Spanish tests. Twenty of his friends have volunteered to participate in his study. He randomly assigns 10 friends to drink water and 10 to drink coffee. All 20 participants take the same math test. He calculates the mean for each group and determines that the mean for the coffee group was 90% and the mean for the water group was 80%. To test the difference of means, he re-randomized the data 200 times, and the differences are plotted in the dot plot below. What can Sam conclude from her study?

Question

gavin39 · Answer

The difference in the means is not significant because a difference of 10 is very likely. 

 The difference in the means is not significant because a difference of 10 is not very likely. 

 The difference in the means is significant because a difference of 10 is very likely. 

 The difference in the means is significant because a difference of 10 is not very likely.

gavin39 · Answer

@minoz