Hermione Granger wants to know if a class of wizards is better able to turn a statistics textbook into a pile of gold if they cast their transfiguration spell out loud with their eyes open, out loud with their eyes closed, or silently with their eyes open. One third of the class tries each version of the spell. You get the following F-test results: F(2,147) = 3,67, p=.032. How many total students participated?

O 147
O 6
Ο 150
O 145