The study on Price ($) and Sales of automobiles resulted in the following data: Use the following formula to calculate the correlation r between the Sakes (Y) and the price (X) in the table below: Price (X) 10 20 30 40 50 60 70 80 90 100 Sales (Y) 28 25 25 19 15 12 9 10 6 5 Use the variables and numbers in the table above to calculate the equation of the regression line: is the predicted value of y (Sales) using x (Cost) with bo (the sample intercept) and b1 (the sample slope).

A. Calculate b1 (3 marks) ANSWER:

B. Calculate b0 (1 marks) ANSWER:

C. Write the equation of the regression line (1 mark): ANSWER:

D. What is the estimated value, for x = 15? (2 marks)