The average weight of a family of five members whose weights are 40 kg, 49 kg,…

Concept

The arithmetic mean represents an equal share of a total across all observations.

For n observations, mean = (sum of all observations) / n.

Application

1. Add the first two weights: 40 + 49 = 89 kg.

2. Include the third weight: 89 + 57 = 146 kg.

3. Include the fourth weight: 146 + 77 = 223 kg.

4. Include the fifth weight: 223 + 36 = 259 kg.

5. Divide the total by the five members: 259 / 5 = 51.8 kg.

Cross-check

Multiplying the computed mean by the number of members gives 51.8 × 5 = 259 kg, which reproduces the original total.

Therefore, the average weight is 51.8 kg.