1. The problem statement, all variables and given/known data Suppose two variables x and y are known to satisfy a relation y=Bx. That is a graph of x vs. y is a line through the origin. Suppose further that you have N measurements (xi,yi)and that the uncertainties in x are negligible and those in y are equal. Prove the best estimate for B is B= [Sum(xy)]/[Sum(x^2)] 2. Relevant equations B= [(N Sum(xy))-(Sum(x))*(Sum(y))]/[Del] Del = [N(Sum(x^2))] - (Sum(x))^2] 3. The attempt at a solution[/b] So I plugged the equation of Del into the equation for B so I can try to simplify it and therefor show the best estimate. But it just gets more and more complicated. Is that for sure where I should start?