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What is the r-value of the following data to three decimal places?

x
y
2 15
6 13
7 9
8 8
12 5
A. 0.953
B. -0.953
C. 0.909
D. -0.909

User Bgoldst
by
8.0k points

1 Answer

6 votes

Answer:

Option B

Explanation:

Given that two variables in table as

Total Average

x 2 6 7 8 12 35 7

y 15 13 9 8 5 50 10

xy 30 78 63 64 60 295 59

(x-7)^2 25 1 0 1 25 52 10.4

(y-10)^2 25 9 1 4 25 64 12.8

Var x = 10.4 and std dev x = 3.225

Var Y = 12.8 and std dev Y = 3.578

Cov (xy) = E(xy)-E(x) E(Y)=59-70=-11

Correlation coefficient r

= Cov /sx sy = -11/(3.225)(3.578)=-0.9532

Round off to get

r=-0.953

Henceoption B is right.

User Eddie Hartman
by
7.8k points