Question

STATISTICS.
We are learning how to model a scatterplot using a linear regression. Why is it that in a residual plot, the mean is equal to 0? Recall that the values of the residuals may be determined by:

residual = (actual y-val) - (predicted y-val)

Answer 1

So residuals are like the values we are off by

Answer 2

This is going to be zero only for unbiased estimator.