In a given population of two-earner male/female couples, male earnings have a mean of $40,000 per year and a standard deviation of $12,000. Female earnings have a mean of $45,000 per year and a standard deviation of $18,000. The correlation between male and female earnings for a couple is 0.80. Let C denote the combined earnings for a randomly selected couple. a. What is the mean of C?b. What is the covariance between male and female earnings?c. What is the standard deviation of C?