3 DETAILS MY NOTES The graph shows the depth of water W in a reservoir over a one-year period as a function of the number of days x since the beginning of the year. What was the average ra x = 0 and x = 300? (Assume that the points lie on the grid lines.) 1 x ft/day W (ft) 250 225 200 175 150 125 100 75 50 25 x (days) 50 100 150 200 250 300 350 400