q. calculate corelation coefficient

x ; 65 66 57 67 68 69 70 72

y ; 67 56 65 68 72 72 69 71

from dis formula ;

r= ∑xy ∕ Nsd(x) sd(y)

X Y x=X-X¯ x2 y=Y-Y y2 xy
65  67 -1.75 3.0625 -0.5 0.25 0.875
66 56 -0.75 0.5625 -11.5 132.25 8.625
57 65 -9.75 95.0625 -2.5 6.25 24.375
67 68 0.25 0.0625 0.5 0.25 0.125
68 72 1.25 1.5625 4.5 20.25 5.625
69 72 2.25 5.0625 4.5 20.25 10.125
70 69 3.25 10.5625 1.5 2.25 4.875
72 71 5.25 27.5625 3.5 12.25 18.375
X=534 Y=540   x2=143.5     xy=73

X¯ =XN=5348=66.75Y¯ =YN=5408=67.5r=xyx2×y2=73143.5×194=73166.85=0.43

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