Asked by EZRA

THE AVERAGE MARK OF 4 GIRLS IN A SCIENCE TEST IS 6,THE MARKS OF 3 OF ZM ARE 5,7,4.FIND THE MARK OF THE 4TH GIRL.
Answered by PsyDAG
First, please do not use all capitals. Online it is like SHOUTING. Not only is it rude, but it is harder to understand. Thank you.

Mean = ∑x/n

6 = (5+7+4+x)/4

Solve for x.