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 professional baseball players gave the following information (Reference: The Baseball Encyclopedia, Macmillan Publishing Company):

(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 ˆ‘x 5 1.957, ˆ‘x2 ‰ˆ 0.553, ˆ‘y = 30.1, ˆ‘y2 = 150.15, and ˆ‘xy ‰ˆ 8.753. Compute r. As x increases, does the value of r imply that y should tend to increase or decrease? Explain.

x0.243 0.259 0.286 0.263 0.268 0.339 0.299 5.0 1.4 3.6 5.5 3.8 3.5 7.3