The following data gave X = the water content of snow on April 1 and Y = the yield from April to July (in inches) on the Snake River watershed in Wyoming for 1919 to 1935. (The data were taken from an article in Research Notes,Vol. 61, 1950, Pacific Northwest Forest Range Experiment Station, Oregon). x 23.1 32.8 31.8 32.0 30.4 24.0 39.5 24.2 52.5 37.9 30.5 25.1 12.4 35.1 31.5 21.1 27.6 y 10.5 16.7 18.2 17.0 16.3 10.5 23.1 12.4 24.9 22.8 14.1 12.9 8.8 17.4 14.9 10.5 16.1 (a) Estimate the correlation between Y and X. Round your answer to 3 decimal places
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Answer:
Answer:r=0.933Step-by-step explanation:X = the water content of snow on April 1 Y = the yield from April to July (in inches) on the Snake River watershed in Wyoming for 1919 to 1935.x: 23.1 32.8 31.8 32.0 30.4 24.0 39.5 24.2 52.5 37.9 30.5 25.1 12.4 35.1 31.5 21.1 27.6y: 10.5 16.7 18.2 17.0 16.3 10.5 23.1 12.4 24.9 22.8 14.1 12.9 8.8 17.4 14.9 10.5 16.1We can construct the following tablen [tex]\sum x[/tex] [tex]\sum y[/tex] [tex]\sum x^2[/tex] [tex]\sum y^2[/tex] [tex]\sum xy[/tex]______________________________________________1 23.1 10.5 533.61 110.25 242.552 32.8 16.7 1075.84 278.89 547.763 31.8 18.2 1011.24 331.24 578.764 32.0 17.0 1024 289 5445 30.4 16.3 924.16 265.69 495.526 24.0 10.5 600.25 110.25 2527 39.5 23.1 1560.25 533.61 912.458 24.2 12.4 585.64 153.76 300.489 52.5 24.9 2756.25 620.01 1307.2510 37.9 22.8 1436.41 519.84 864.1211 30.5 14.1 930.25 198.81 430.0512 25.1 12.9 630.01 166.41 323.7913 12.4 8.8 153.76 77.44 109.1214 35.1 17.4 1232.01 302.76 610.7415 31.5 14.9 992.25 222.01 469.3516 21.1 10.5 445.21 110.25 221.5517 27.6 16.1 761.76 259.21 444.36____________________________________________On this case n=17, [tex]\sum x = 511.5[/tex] [tex]\sum y=267.1[/tex] [tex]\sum x^2 =16628.65[/tex] [tex]\sum y^2 =4549.43[/tex] [tex]\sum xy =8653.45[/tex]And we can use the following formula to calculate the correlation coefficient:[tex]r=\frac{n(\sum xy)-(\sum x)(\sum y)}{\sqrt{[n\sum x^2-(\sum x)^2][n\sum y^2-(\sum y)^2]}}[/tex]And replacing we have:[tex]r=\frac{17(8653.45)-(511.5)(267.1)}{\sqrt{[17(16628.65)-(511.5)^2][17(4549.43)-(267.1)^2]}}=0.933[/tex]
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