If two loads are applied to a cantilever beam as shown in the accompanying drawing, the bending moment at 0 due to the loads is a1X1 a2X2.

c. With Xi denoting the number of cars entering from road i during the period, suppose that Cov(X1, X2) 80, Cov(X1, X3) 90, and Cov(X2, X3) 100 (so that the three streams of traffic are not independent). Compute the expected total number of entering cars and the standard deviation of the total.