1. The problem statement, all variables and given/known data I have a table with a data set #, and 2 variables (W and P) with values in the table. 2. Relevant equations The equation (which I don't know what it means) says V= (summation with n on top and i=1 below Wi X Pi)/(summation with n on top and i=1 on bottom X Pi) 3. The attempt at a solution What are the summations meaning and what do the subscript "i"'s mean?