Question

A hotel hosts three types of events: expositions (E), conferences (C) and wedding receptions (W). The profits made by these events vary. The profits made on expos average $7000 and vary independently with standard deviation $1500. The profits made on conferences average $6000 and vary independently with standard deviation $1000. The profits made on wedding receptions average $4000 and vary independently with standard deviation $1500. Let us suppose that the profits for expos and conferences are slightly negatively correlated with ρ_EC = -0.3, the profits for expos and wedding receptions are independent, but the profits for conferences and wedding receptions are slightly positively correlated with ρ_CW = 0.4

(ρ_EC means correlation between expositions and conferences )

Calculate the standard deviation of expos and conferences together(don't round, use 2 decimal points)

Answer 1