Answer:
(A) 7.66
Step-by-step explanation:
[tex]Mean=\dfrac{\text{Total Score}}{\text{Number of Scores}}[/tex]
Total Score= Mean X Number of Scores
For the girls, Mean Score=8.25, Number of Scores = 12
For the boys, Mean Score=7.3, Number of Scores = 20
Total Score for all Students = 99+146=245
Total number of students = 20+12=32
[tex]\text{Mean Score of all the students}=\dfrac{\text{Total Score}}{\text{Number of Scores}}\\\text{Mean Score of all the students}=\dfrac{245}{32}=7.66[/tex]