The probability distribution associated with the tossing of a pair of fair dice was described in Section 8.2 and shown in Table 8.4 and Figure 8.1. The random variable of interest in that case was the sum of the values on the upfacing sides of the two dice following the toss. This may appear simple, and in many respects it is simple, but it actually is an example of a rather complex situation. The values of the random variable, the


values, upon which the distribution is based, are sums of values obtained from

two different sources

, the two dice.