On December 24, 1982 the state of Colorado had a huge snowstorm, dropping close to 30 inches of snow in parts of the state. Approximate snowfall levels are shown in the contour diagram below. The state of Colorado is roughly a rectangle 388 miles wide and 276 miles tall. The gridline sub-rectangles shown in the plot below are about 43 miles wide and 40 miles from top to bottom. By estimating the snowfall level at the middle of each of these sub-rectangles (i.e. at the shown "points"), estimate the total snowfall amount (this will be a volume with odd units, namely miles^2*inches, but there is no need to convert it to more meaningful units), and the average amount of snow (in inches) for the entire state.