The residual value is an estimate of the wholesale value .To find the residual value we plug in x=4 in the given line of best fit.The corresponding y value will give the predicted value.
y=2.78x-4.4
Substituting x=4,
y=2.78(4)-4.4
y=11.12-4
y=7.12.
The predicted value when x=4 is y=7.12.
Residual value = predicted value - Actual value -=7.12 - actual value.
You plug 4 into the line of best fit and get 6.72. This is your predicted value, but the residual is the difference between the actual value and predicted. So you subtract: 7.3-6.72=0.58.
They tell you that the length is 7 inches and that it is 2 inches more than the width therefore you can conclude that: length = 7 and the width = 5 you can plug the values given into the formula listed below:
