The maximum power output capability of a gasoline or diesel engine decreases with altitude because the air density and hence the mass flow rate of air decreases. A truck leaves Denver (elevation 5280 ft) on a day when the local temperature and barometric pressure are 80 F and 24.8 in. of mercury, respectively. It travels through Vail Pass (elevation 10,600 ft), where the temperature is 62 F. Determine the local barometric pressure at Vail Pass and the percent change in density.