EXAMPLE 25Uniform probability distribution
Using the uniform probability distribution in Figure 20, calculate the probability that you will wait the following amount of time for the campus shuttle bus:
Solution
We are interested in the interval between and minutes. The area above this interval forms a rectangle, shown in Figure 21. The area of this green rectangle represents the probability that is between 2 and 4 minutes. The base of the rectangle equals . The height of the rectangle equals 0.1, so we find that the area of this rectangle is
Because area represents probability, we conclude that the probability is 0.2 that you will wait between 2 and 4 minutes for the campus shuttle bus.
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NOW YOU CAN DO
Exercises 11–20.