The fuel consortium chairman at an airport recorded the
cost per barrel of crude oil and the cost per barrel of jet
fuel each week.
After plotting his results, the chairman noticed that the
relationship between the two variables was fairly linear,
so he used the data to calculate the following least
squares regression equation for predicting the cost, in
dollars, per barrel of jet fuel from the cost, in dollars, per
barrel of crude oil.
ŷ = 2+ = x
What is the residual of a week in which a barrel of
crude oil costs $60 and a barrel of jet fuel costs $78 ?