Four friends are contemplating joining a local bowling league. Let X1, X2, X3, X4 be the score of the first, second, third, and fourth friend, respectively, on a randomly chosen game. From past experience, the friends know that: E( X1 ) = 110, E( X2 ) = 125, E( X3 ) = 113, and E( X4 ) = 140. Additionally, sigma subscript 1 = 7, sigma subscript 2 = 13, sigma subscript 3 = 10, and sigma subscript 4 = 20. Define their total score on a randomly chosen game as Y = X1 + X2 + X3 + X4. Assume the four players' scores are independent. Calculate the variance of their total score on a randomly chosen game