A researcher varies the amount of caffeine given to three groups of participants (0, 100, and 200 mg) and then observes the anxiety level for each group. The most appropriate statistical test used to determine whether the groups differ is

What is the simplified form of 7 √x • 7 √x • 7 √x • 7 √x?

If the ratio of sum of the first m and n terms of an ap is m2 : n2 , show that the ratio of its mth and nth terms is (2m − 1) : (2n − 1).

"curse these trig-loving pirates! " devora mutters as she looks at the map. then, after thinking for a moment, she walks back to the entrance of the secret cave, measuring 48 meters along the way. after performing a calculation, devora walks back to the empty treasure, faces the entrance, and turns a certain number of degrees to her left before walking 89 meters to the treasure. supposing that the angle at the cave entrance is acute and that devora's calculations were correct, how many degrees did she turn?