Given below is the observed data of the ages of various children.
| Age in years | Number of children |
| 6 | 8 |
| 7 | 3 |
| 8 | 7 |
| 9 | 2 |
| 10 | 20 |
What is the mean of the ages of the children?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 8.575 years.
Mean of ages = Sum of ageds/Number of children
According to the given table,
Sum of the ages of all children = (8 × 6) + (7 × 3) + (8 × 7) + (9 × 2) + (10 × 20)
⇒ 48 + 21 + 56 + 18 + 200 = 343
Total number of children = 8 + 3 + 7 + 2 + 20 = 40
Mean = 343/40 = 8.575