For Exercises 2.23 and 2.24, see page 75; and for 2.25 and 2.26, see pages 77–78.

Question 2.43

2.43 Sloppy writing about correlation

Each of the following statements contains a blunder. Explain in each case what is wrong.

  1. “The correlation between and is but the correlation between and is .”
  2. “There is a high correlation between the color of a smartphone and the age of its owner.”
  3. “There is a very high correlation () between the premium you would pay for a standard automobile insurance policy and the number of accidents you have had in the last three years.”

2.43

(a) The correlation is not dependent on order and remains the same between two variables regardless of order. (b) A correlation is reserved for quantitative data; because color is categorical, it cannot have any correlation. (c) A correlation can never exceed 1, which indicates a perfect linear relationship.