Question

The mean weight of 45 boys is 65kg and 37 girls is 45kg and that of 5 teachers is 70kg. What is the average weight of the whole class included the teachers?

Answer 1

The average weight of the whole class is: 56.78kg

Step-by-step explanation:

Given

`\bar x_(boys) = 65`

`n_(boys) = 45`

`\bar x_(girls) = 45`

`n_(girls) = 37`

`\bar x_(teachers) = 70`

`n_(teachers) = 5`

Required

The average of the whole class.

This requires that we calculate the population average

This is calculated as:

`\mu = (\sum n_i * \bar x_i)/(\sum n)`

So, we have:

`\mu = (45 * 65+ 37*45+5*70)/(45+37+5)`

`\mu = (4940)/(87)`

`\mu = 56.78`