EXAMPLE 4.28
The mean of equally likely first digits. If first digits in a set of data all have the same probability, the probability distribution of the first digit X is then
| First digit X | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
| Probability | 1/9 | 1/9 | 1/9 | 1/9 | 1/9 | 1/9 | 1/9 | 1/9 | 1/9 |
The mean of this distribution is