Question

The formula of direct mean method is.

Answer 1

∑i=1nf= Sum of all the frequencies. This is also denoted by N. ∑i=1nfixi= Sum of the product of frequencies and corresponding observations.

Answer 2

$\rm\: The \: formula \: of \: direct \\ \rm \: mean \: method \: is: - \\ \\ \sf \:Mean = \: \frac{\sum{fixi}}{\sum{fi}}$