5. Suppose x1 N(1, 5), x2 N(2, 3), and x3 N(2.5, 7), with correlations 1,...

5. Suppose x1∼ N(1, 5), x2 ∼ N(2, 3), and x3 ∼ N(2.5, 7), with correlations ρ1, 2 =

0.3, ρ1, 3 = 0.1, and ρ2,3 = 0.4. What is the distribution of x1+ x2 + x3? x1+ (3×

x2) + x3? x1+ x2 + (0.5× x3)?