3. [15 points] An automobile dealer wants to estimate monthly sales based on the interest rate. A random sample of 4 months was taken. The results of the sample are presented below. X=Interest Rate (%) 9.2 7.6 10.4 5.3 Y=Monthly Sales ($1000s) 22 20 10 45 (a) Find the estimated regression equation to predict monthly sales based on the interest rate by computing the values of bo and b. (b) Predict monthly sales of one month with a 10% interest rate. Give your answer in dollars. (c) Would the sales ever reach zero? If yes, at what interest rate would the sales be zero? (a) Can you tell how much error in your estimate in part (d)? Explain clearly.