Astronomers have discovered that, with the exception of a few nearby galaxies, all galaxies in the universe are moving away from us. Moreover, the farther the galaxy, the faster it is moving away. That is, the more distant a galaxy, the greater the speed at which it is moving away from us.

Exercises 9–16 make statements about a correlation. In each case, state the correlation clearly. (For example, we might state that “there is a positive correlation between variable A and variable B.”) Then state whether the correlation is most likely due to coincidence, a common underlying cause, or a direct cause. Explain your answer.