In fact, let's use the formula for an area of a trapezoid. The formula for an area of a trapezoid is you would take the average of, you would take the average of this length, let me do that in another color, this length and this length, and then multiply that times the base. So the average of this length and this length, let's see, this is 0.25, 0.25 plus this height, 0.75 divided by two, so that's the average of those two sides, times the base, times this right over here, which is two. And so this is going to give us, as it should have, 0.25 plus 0.75, which is equal to one. So the area under the entire density curve is one, which we need to be true for this to be a density curve. Now let's think about what percentage of that area is represented in blue right over here. Well, we could do the same thing.