You are the foreman of the Bar-S cattle ranch in Colorado. A neighboring ranch has calves for sale, and you are going to buy some calves to add to the Bar-S herd. How much should a healthy calf weigh? Let x be the age of the calf (in weeks), and let y be the weight of the calf (in kilograms). 39 47 73 100 1 26 36 0 200 Complete parts (a) through (e), given Ex = 95, Zy = 609, Ex2 = 2375, Ey2 = 81,559, Exy = 13,777, and r = 0.997. (a) Make a scatter diagram of the data. (Select the correct graph.) CHOICE A CHOICE B CHOICE D CHOICE C 200 200 200 200 150 150 150 150 100 100 100 100 8 50 20 X 40 X 10 20 30 40 O 20 O 30 40 10 O 20 30 40 (b) Verify the given sums Ex, Ey, Ex2, Ey2, Ex y, and the value of the sample correlation coefficient r. (For each answer, enter a number. Round your value for r to three decimal places.) SX = 95 Ey = 609 Ex2 - X X Ey2 = Exy = r= (c) Find x, and y. Then find the equation of the least-squares line y = a + b x. (For each answer, enter a number. Round your answers for x and y to two decimal places. Round your answers for a and b to three decimal places.) (d) Graph the least-squares line. Be sure to plot the point (x, y) as a point on the line. (Select the correct graph.) CHOICE A CHOICE B CHOICE C CHOICE D 200 200 200 200 150 150 150 150 100 LOO 100 8 10 20 30 40 10 20 30 40 10 20 X O o 30 O 40 10 20 30 O 40 (e) Find the value of the coefficient of determination 2. What percentage of the variation in y can be explained by the corresponding variation in x and the least-squares line? What percentage is unexplained? (For each answer, enter a number. Round your answer for 2 to three decimal places. Round your answers for the percentages to one decimal place.) 2 = 0.994 explained = 99.4 % unexplained = 0.6 % (f) The calves you want to buy are 25 weeks old. What does the least-squares line predict for a healthy weight (in kg)? (Enter a number. Round your answer to two decimal places.) x kg Need Help? Read It