Question

@agent0smith

Answer 1

http://prntscr.com/b1xi2r this part is what im having a hard time understanding

Answer 2

The graph just shows the difference of the two means if you took all the test grades, broke them into two random groups, got the mean of each and the difference, and then plotted the difference on that graph

Answer 3

random groups?

Answer 4

Yeah like collect all the tests and then just break them into two random groups