Question

I need help with this question pleas urgent!

Answer 1

75.5

Explanation:

To calculate the mean we use

mean =
`(score)/(count)`

To calculate the mean for class B we require their score

Using the mean for class A

`(score)/(25)` = 67.8 ( multiply both sides by 25 )

score = 67.8 × 25 = 1695

Similarly using the mean for all 55 students

`(totalscore)/(55)` = 72 ( multiply both sides by 55 )

total score = 72 × 55 = 3960

Hence score for class B = 3960 - 1695 = 2265

mean for class B =
`(2265)/(30)` = 75.5