Question 4.123

4.123 What happens if the correlation is not zero?

Suppose that is a random variable with mean 20 and standard deviation 5. Also suppose that is a random variable with mean 40 and standard deviation 10. Assume that the correlation between and is 0.5. Find the variance and standard deviation of the random variable for each of the following cases. Be sure to show your work.

  1. .
  2. .
  3. .

4.123

(a) (b) (c)