EXAMPLE 4.12 Find More Probabilities for Benford's Law

CASE 4.1 Check that the probability of the event that a first digit is even is

Consider again event from Example 4.11 (page 185), which had an associated probability of 0.602. The probability

is not the sum of and because events and are not disjoint. The outcome of 2 is common to both events. Be careful to apply the addition rule only to disjoint events. In Section 4.3, we expand upon the addition rule given in this section to handle the case of nondisjoint events.