Chapter 7.1, Problem 7.8E

(a)

To determine

To Calculate: the two outcomes have exactly the same probability.

Answer to Problem 7.8E

  $\frac{1}{1000}$

Explanation of Solution

Calculation:

The selection of each digit has a probability of 1 in 10 so the probability of selecting of foru numbers (any combination) is

  $\begin{array}{l}=\frac{1}{10}\times \frac{1}{10}\times \frac{1}{10}\times \frac{1}{10}\\ =\frac{1}{1000}\end{array}$

Every number has the same probability of being selected.

(b)

To determine

To Explain: the probability for 9999 and 2873.

Explanation of Solution

Most people will be thinking that the less likely to be elected in 9999, because the probability of a number with all the same digits is being selected less than the number to be chosen with four different digits. Thus the most people will favour 2873.