Last year the? retailer's weekly variance of demand was 190 units. The variance of orders was 480 ?, 590 ?, 770 ?, and 1 comma 320 ?units, for the? retailer, wholesaler,? distributor, and? manufacturer, respectively.? (Note that the variance of orders equals the variance of demand for that? firm's supplier.) ?a) The bullwhip measure for the retailer is