HSC Commerce 12th Board ExamMaharashtra State Board
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# Coefficient of rank correlation between x and y is 0.5 and ∑d2i= 42. Assuming that no ranks are repeated, find the number of pairs of observations. - HSC Commerce 12th Board Exam - Mathematics and Statistics

#### Question

Coefficient of rank correlation between x and y is 0.5 and sumd_i^2= 42. Assuming that no ranks are repeated, find the number of pairs of observations.

#### Solution

r=0.5

sumd_i^2=42

n=?

R=1-(6sumd_i^2)/(n(n^2-1))

0.5=1-(6(42))/(n(n^2-1))

=1-252/(n(n^2-1))

252/(n(n^2-1))=1-0.5

252/(n(n^2-1))=0.5

(n(n^2-1))=252/0.5xx10/10

=504

put n=10

10(99)=990

put n=9

9(80)=720

put n=8

8(63)=504

therefore n=8

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#### APPEARS IN

2014-2015 (March) (with solutions)
Question 4.3 | 2.00 marks

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Solution Coefficient of rank correlation between x and y is 0.5 and ∑d2i= 42. Assuming that no ranks are repeated, find the number of pairs of observations. Concept: Rank Correlation.
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