# Question #a920f

##### 2 Answers

#### Explanation:

Out of 44

The 'Expectation' (mean value) is

Mean =

#### Explanation:

To find the mean of a set of date we use the following method:

Remember, we can add numbers, we can add totals,

WE CANNOT ADD MEANS!

For the 44 boys in the class , we can find the sum of all their ages.

9 boys are all 10 years old, the sum of their ages is

15 boys are all 9 years old, the sum of their ages is

20 boys are all 8 years old:, the sum of their ages is

For the 44 boys, the sum of their ages is 385 years.

Mean =