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liberty university BUSI 230-week-8-review-and-exam-2019/20-complete-answers explanation.-A-rated-answers

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Question 1) Is the magnitude of an earthquake related to the depth below the surface at which the quake occurs? Let x be the magnitude of an earthquake (on the Richter scale), and let y be the depth (... in kilometers) of the quake below the surface at the epicenter. x 2.9 4.7 3.3 4.5 2.6 3.2 3.4 y 4.6 10.3 11.2 10.0 7.9 3.9 5.5 (b) Use a calculator to verify that Σx = 24.6, Σx2 = 90.20, Σy = 53.4, Σy2 = 460.56 and Σxy = 195.43. Compute r. (Round to 3 decimal places.) 2) 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. x 0.251 0.251 0.286 0.263 0.268 0.339 0.299 y 1.2 3.7 5.5 3.8 3.5 7.3 5.0 b) Use a calculator to verify that Σx = 1.957, Σx2 = 0.553, Σy = 30.0, Σy2 = 150.36 and Σxy = 8.710. Compute r. (Round to 3 decimal places.) Answers. (a) r = 0.550 (b) r =0.894 Explanation: Given values are verified and they are correct. Pearson correlation coefficient is given by r = Sxy / (Sxx * Syy)1/2 Sxy = Σxy - (( Σx * Σy ) /n ) Sxx = Σx2 - ((( Σx )^2) /n ) Syy = Σy2 - ((( Σy )^2) /n ) (a) Sxx = Σx2 - ((( Σx )^2) /n ) = 90.20 - ((24,6)^2 / 7) = 3.74857 Syy = Σy2 - ((( Σy)^2) /n ) = 460.56 - ((53.4)^2 / 7 ) = 53.143, Sxy = Σxy - (( Σx * Σy ) /n ) = 195.43 - ((24.6*53.4)/7) = 7.7671 Substituting the above values in the formula r = Sxy / (Sxx * Syy)1/2 We get r = 0.550 (b) Following the exact method as above, we get r =0.894 The answers are below: Explanation: 3. (a) Draw a scatter diagram displaying the data. [Show More]

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