Two random variables x and y are independent if the value of x does not affect the value of y. if the variables are not independent, they are dependent. a new random variable can be formed by finding the sum or difference of random variables. if a random variable x has mean mu subscript x and a random variable y has mean mu subscript y then the means of the sum and difference of the variables are given by the following equations. mu subscript x plus y baseline equals mu subscript x baseline plus mu subscript y nbsp mu subscript x minus y baseline equals mu subscript x baseline minus mu subscript y the distribution of a test's scores for college-bound male seniors has a mean of 1528 and a standard deviation of 312. the distribution of a test's scores for college-bound female seniors has a mean of 1490 and a standard deviation of 300. one male and one female are randomly selected. assume their scores are independent. what is the average sum of their scores