Question

Class A has 11 pupils and class B has 15 pupils.

Both classes sit the same maths test.
The mean score for class A is 77.
The mean score for both classes is 49.
What is the mean score (rounded to 2 DP) in the maths test for class B?
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Answer 1

The mean score in the math test for class B=28.47

Explanation:

Step 1: Determine the total number of students in both Classes

Total number of students=number in class A+number in class B

where;

number in class A=11 pupils

number in class B=15 pupils

replacing;

Total number of students=11+15=26 students

Step 2: Determine total score for both classes

Total score for both classes=total score for class A+total score for class B

total score for both classes=mean score for both classes×total number of students

total score for both classes=(49×26)=1,274

total score for class A=mean score for class A×total number of class A students

total score for class A=(77×11)=847

total score for class B=mean score for class B×total number of class B students

total score for class B=m×15=15 m

replacing;

1,274=847+15 m

15 m=1,274-847

15 m=427

m=427/15=28.47

The mean score in the math test for class B=28.47