Let the random variable X be a random number with the uniform density curve given below.

P(0.7 < X < 1.1) has value ______.

A. 0.30
B. 0.40
C. 0.70

Correct Answer: A

Because the density ends at 1, there is no probability associated with X values greater than 1. So P(0.7 < X < 1.1) is the same as P(0.7 < X < 1.0). If you shade this region in the density, the result is a rectangle with a length 1.0 - 0.7 = 0.3 and a height of 1.0, so the area is 0.3 x 1.0 = 0.3.