Recall that the density function for a uniform distribution is constant over an interval, resulting in a horizontal density curve. Because the density curve forms a rectangle and the area under the curve must equal 1, we can calculate the area under the curve using the formula area = (base)(height) = 1. It is given an interval of 0 to 1,000 km for the density function. Within that interval, the density function has a certain constant probability, and outside of that interval, the probability is 0. Using the interval 0 to 1,000 as the length of the base, compute the height of the density curve rectangle. area = (base)(height) 1 = 1,000 (height) = height