The formula for finding mean by direct method is
∑(A×B)∑A
where B and A are respectively are _______.
Given, Mean = ∑(A×B)∑A........(i)
∵Mean (¯¯¯x)=∑fx∑f ..........(ii)
where, 'f' is the frequency of a class
'x' is the class mark of the class
Now, comparing (i) and (ii), we get,
'A' is the frequency of the class
and 'B' is the class mark.