II.13. Outliers. African elephants are much larger than any other mammal in the data set but lie roughly in the overall straight-line pattern. Dolphins, humans, and hippos lie outside the overall pattern. The correlation between body weight and brain weight for the entire data set is r = 0.86.
(a) If we removed elephants, would this correlation increase, decrease, or not change much? Explain your answer. (Hint: See page 326.)
(b) If we removed dolphins, hippos, and humans, would this correlation increase, decrease, or not change much? Explain your answer. (Hint: See page 326.)