how many observations in a x$ variable which condition would be the only condition which might negatively affect the explanatory variables how do you figure the weighted sum of the summation of variables what is the sum of an explanatory value what is the weight of an observation what is the weighted sum of variables weighted sum analysis for y$ how many observations are there in one $x$ variable how many observations are in the sum of x$ how do you weight explanatory variables weighted weight of explanatory variables why do variables behave additively in a regression how many observations in a variable in regression how to calculate weighted sum from an independent sample what is the arithmetic of a summarized variable what makes an observation additive how much does it cost to weight the sum of a variable? weighted sum of the variables in x how do i find out the value of x in a weighted sum of variables weighted sum of variables in data