Question

Please help! its due today! Class A has 19 pupils and class B has 14 pupils.

Both classes sit the same maths test.

The mean score for class A is 21.

The mean score for class B is 71.

What is the mean score (rounded to 2 DP) in the maths test across both classes?

Answer 1

mean ≈ 42.21

Explanation:

mean is calculated as

mean =
`(sum)/(count)`

to find the mean of both classes we require the sum for each class

class A

`(sum)/(19)` = 21 ( multiply both sides by 19 )

sum = 399

class B

`(sum)/(14)` = 71 ( multiply both sides by 14 )

sum = 994

mean for both classes is then

mean =
`(399+994)/(33)` =
`(1393)/(33)` ≈ 42.21 ( to 2 dec. places )