The Cadet is a popular model of sport utility vehicle known for its relatively high resale value The bivariate data given below were taken from a sample of fifteen Cadets each bought new two years ago and each sold used within the past month For each Cadet in the sample we have listed both the mileage x in thousands of miles that the Cadet had on its odometer at the time it was sold used and the price y in thousands of dollars at which the Cadet was sold used The least squares regression line for these data has equation 39 87 0 42x This line is shown in the scatter plot below Mileage x in thousands 27 5 24 0 34 7 29 5 15 6 20 6 27 9 25 9 26 9 20 6 24 0 23 3 22 8 37 5 24 1 Send data to calculator Used selling price y in thousands of dollars 30 3 27 3 26 4 28 0 33 9 31 4 25 6 27 3 30 6 30 3 29 8 32 9 31 0 23 6 28 7 Based on the sample data and the regression line complete the following dumas pas In thousands of d Mileagex in thousands a For these data mileages that are less than the mean of the mileages tend to be paired with used selling prices that are Choose one the mean of the used selling prices b According to the regression equation for an increase of one thousand miles in Cadet mileage there is a corresponding decrease of how many thousand dollars in the used selling price X