Question 155341
Find the value for the correlation coefficient r.
x = 5 , x= 1
y= 5 , y = 10
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There are at least two formulas for "r".
One of them is 
r = [Summation(x-xbar)(y-ybar)]/(n-1)sxsy
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n=2
xbar = 3 ; ybar = 7.5
sx = 2.83 ; sy = 3.54
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r = [(5-3)(5-7.5) + (1-3)(10-7.5)]/ (2-1)*2.83*3.54

= [2*-2.5 + -2*2.5]/10 = -1

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Cheers,
Stan H.