I want to know that how do deal with the data that has some measurement uncertainties in it. So for example, Let's say I have a set of population densities data for different counties and I want to calculate the average population density. Then I look at three scenarios- 1) I take the weight as area of counties and 2) I take the weight as population of the counties and 3) Simply take the average. Which one of these two choices will handle the census errors more clearly? So, I have no way of knowing what kind of uncertainties were involved in the experiment. In that case what is the best case scenario for handling the data for statistical tests? Also I don't know how many (if there are any) uncertainties are present in the data. So, if I want to tackle this situation mathematically then what should I do? I mean like calculating weighted averages of the values that my variable/s of interest can take or removing the outliers and studying them separately or some other procedure like that!