The figure shows the power consumption in San Francisco for a day in September P is measured in megawatts t is measured in hours starting at midnight P MW 4 800 600 400 200 0 3 6 9 12 15 18 21 a What was the power consumption at 6 00 A M MW What was the power consumption at 6 00 P M MW b When was the power consumption the lowest t h c When was the power consumption the highest t h t h d Find the net change in the power consumption from 9 00 A M to 7 00 P M MW