Step 2 With the known values of a = 30 and b = 40, the height of the rectangle can be found using b - Find the height of the graph for this probability density function. height = b - a = 40 - 11 Use the values a = 30, b = 40, and the height found above to construct a graph of the probability density function. J( X) f(x) f(x) 0.2- 0.2 0.2 0.15 0.15 0.15 0.15 0.1 0.1 0.1 0.1 0.05 0.05 0.05 0.05 X X X 10 20 30 40 50 10 20 30 40 50 20 30 30 40