13. [-/16 Points] DETAILS BBBASICSTAT8 4.2.008.5. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER 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). y 44 49 16 26 78 100 150 200 LA USE SALT Complete parts (a) through (e), given Ex = 93, Ey = 621, Ex? = 2335, Ey? = 82,921, Exy = 13,691, and r = 0.9960. (a) Draw a scatter diagram displaying the data. 200 35 30 150 25 y (calf weight (in kilograms)) 20 y (calf weight (in kilograms) 100 10 50 5 10 15 20 30 35 50 100 150 200 O x (age of calf (in weeks)) x (age of calf (in weeks)) y (calf weight (in kilograms)) 100 150 200 O x (age of calf (in weeks)) 200 150 y (calf weight (in kilograms)) 100 10 15 20 25 30 35 O x (age of calf (in weeks)) (b) Verify the given sums Ex, Ey, Ex?, Ey?, Exy, and the value of the sample correlation coefficient r. (Round your value for r to four decimal places.) Ex =50 100 150 200 O x (age of calf (in weeks)) 200 150 y (calf weight (in kilograms)) 100 5 10 15 20 25 30 35 x (age of calf (in weeks)) b) Verify the given sums Ex, Zy, Ex?, Ey?, Exy, and the value of the sample correlation coefficient r. (Round your value for r to four decimal places.) Ex Ey= Ex? Exy (c) Find x, and y. Then find the equation of the least-squares line y = a + bx. (Round your answers to four decimal places.) *= y = 1 = (d) Graph the least-squares line. Be sure to plot the point (x, y) as a point on the line. 200 200 150 150 y (calf weight (in kilograms)) y (calf weight (in kilograms)) y (calf weight (in kilograms)) y (calf weight (in kilograms)) 100 100 10 50 50 of 10 15 20 25 30 35 50 100 150 200 10 15 20 25 30 35 50 100 150 200 x (age of calf (in weeks)) x (age of calf (in weeks)) O x (age of calf (in weeks)) x (age of calf (in weeks)) (e) Find the value of the coefficient of determination . 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? (Round your answer for / to four decimal places. Round your answers for the percentages to two decimal place.) explained unexplained f) The calves you want to buy are 24 weeks old. What does the least-squares line predict for a healthy weight? (Round your answer to two decimal places.) Need Help? Read It Submit Answer Viewing Saved Work Revert to Last Response