A study was made by a retail merchant to determine

A study was made by a retail merchant to determine the relation between weekly advertising expenditures and sales. The following data were recorded:
(a) Plot a scatter diagram.
(b) Find the equation of the regression line to predict weekly sales from advertising expenditures.
(c) Estimate the weekly sales when advertising costs are $35.
(d) Plot the residuals versus advertising costs.Commen