The rank correlation coefficient (r), Mathematics

Assignment Help:

The Rank Correlation Coefficient (R)

Also identified as the spearman rank correlation coefficient, its reasons is to establish whether there is any form of association among two variables where the variables arranged in a ranked form.

R = 1 – {(6Σd2)/(n(n2 -1))}

 

Whereas d = difference among the pairs of ranked values.

                  n = numbers of pairs of rankings

Illustration

A group of 8 accountancy students are tested in Quantitative Techniques and Law II.  Their rankings in the two tests were as:

Student

Q. T. ranking

Law II ranking

d

d2

A

2

3

-1

1

B

7

6

1

1

C

6

4

2

4

D

1

2

-1

1

E

4

5

-1

1

F

3

1

2

4

G

5

8

-3

9

H

8

7

1

1

Σd2 = 22

d = Q. T. ranking - Law II ranking

R = 1 - {(6Σd2)/(n(n2 -1))}

1 -{(6(22))/(8(82 -1))} = 0.74

Hence we conclude that there is a reasonable agreement among student's performances in the two types of tests.

NOTE: in this illustration, if we are given the actual marks then we find r.  R varies between -1 and +1.


Related Discussions:- The rank correlation coefficient (r)

What is this distance expressed in standard notation, The distance from the...

The distance from the sun to the earth is approximately 9.3 × 10 7 miles. What is this distance expressed in standard notation? In order to convert this number to standard not

Definition of inverse functions, Definition of inverse functions :  Given...

Definition of inverse functions :  Given two one-to-one functions f ( x ) and g ( x ) if ( f o g ) ( x ) = x  AND  ( g o f ) ( x ) = x then we say that f ( x ) & g ( x ) are i

Draw a common graph f ( x ) = - x2 + 2x + 3 , Graph        f ( x ) = - x 2 ...

Graph        f ( x ) = - x 2 + 2x + 3 . Solution It is a parabola in the general form.                              f ( x ) = ax 2 + bx + c In this form, the x-coor

What is the meaning of the f-statistic and f test, You are given the follow...

You are given the following regression results estimating the demand for widgets based on time series data for the past 40 months. Q t = 2.5 - 0.3 x P t + 12 x M t Where Q

Calculate the probability, Coal is carried from a rrrine in West Virginia t...

Coal is carried from a rrrine in West Virginia to a power plant in New York in hopper cars on a long train. The automatic hopper car loader is set to put 36 tons of coal in each ca

Matrices, Consider the following linear equations. x1-3x2+x3+x4-x5=8 -2x1+...

Consider the following linear equations. x1-3x2+x3+x4-x5=8 -2x1+6x2+x3-2x4-4x5=-1 3x1-9x2+8x3+4x4-13x5=49

Quadratic equation, What do we mean by the roots of a quadratic equation ?

What do we mean by the roots of a quadratic equation ?

Define tautology and contradiction, Define tautology and contradiction.  ...

Define tautology and contradiction.  Ans: If a compound proposition comprises two atomic propositions as components, after that the truth table for the compound proposition con

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd