Understanding Basic Statistics 6th Edition by Charles Henry Brase,Corrinne Pellillo Brase

تمرين 28

Baseball: Batting Averages and Home Runs In baseball, is there a linear correlation between batting average and home run percentage Let x represent the batting average of a professional baseball player, and let y represent the player's home run percentage (number of home runs per 100 times at bat). A random sample of n = 7 professinal baseball players gave the following information (References: The Baseball Encyclopedia, Macmillam Publishing Comapany).

(a) Make a Scatter diagram and draw the line you think best fits the data.
(b) Would you say the correlation is low, moderate, or high positive or negative
(c) Use a calculator to verify that x = 1.947, x 2 0.553, y = 30.1, y 2 = 150.15 and xy 8.753. Computer r. As x increases, does the value of r imply that y should tend to increase or decrease Explain.