Let x denote the amount of gravel sold (in tons) during a randomly selected week at a particular sales facility. Suppose that the density curve has height f(x) above the value x. Use the fact that the area of a triangle = 1/2(base)(height) to calculate each of the probabilities below: _ 2(11) 03131 [(1) _{ 0 otherwise Density 0 1 Tons (a) P(x