The following age wise chart of 300 passengers flying from Delhi to Pune is prepared by the Airlines staff.
| Age | Less than 10 | Less than 10 | Less than 10 | Less than 10 | Less than 10 | Less than 10 | Less than 10 | Less than 10 |
| Number of passengers | 14 | 44 | 82 | 132 | 184 | 245 | 287 | 300 |
Converting the cumulative frequency table into exclusive classes,
Mean age = `\overline{x}` = `\frac{\sum f i x i}{\sum fi}`
| Age | No of passengers`fi` | `x``i` | `fi``x``i` |
| 0-10 | 14 | 5 | 70 |
| 10-20 | 30 | 15 | 450 |
| 20-30 | 38 | 25 | 950 |
| 30-40 | 52 | 35 | 1820 |
| 40-50 | 50 | 45 | 2250 |
| 50-60 | 61 | 55 | 3355 |
| 60-70 | 42 | 65 | 2730 |
| 70-80 | 43 | 75 | 975 |
| `\sum fi` = 300 | `\sum``fi``x``i` = 12600 |
= `\overline{x}` = `12600/300`
= `\overline{x}` = 42