EXAMPLE 4.29 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 is then
| First digit | 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