Topic: Correlation Analysis

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• Session 2
• Topic Correlation Analysis
• Faculty Ms Prathima Bhat K
• Department of Management Studies
• Acharya Institute of Technology
• Bangalore 90
• Contact prathimabhatk_at_gmail.com
• 9242187131

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PROPERTIES

• Limits for Correlation Coefficient.
• Independent of the change of origin scale.
• Two independent variables are uncorrelated but
  the converse is not true.
• If variable x y are connected by a linear
  equation axbyc0, if the correlation
  coefficient between x y is (1) if signs of a,
  b are different (-1) if signs of a, b are alike.

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IMPORTANT FORMULAS
4
r 0.7804
5
r
2704
v53982224
r 0. 7804
6
r 0.7804
7
r
nS dx.dy - Sdx. Sdy
vnSdx2 (Sdx)2. nS dy2 -(Sdy)2
r
102404 (50)58
v105648 (-50)2 . 102484 (58)2
r 0.78
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r
1045604 650660
v1047648 (650)2 . 1045784 (660)2
r0. 7804
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• From the following data given calculate n
• Correlation coefficient 0.8 Summation of
  product deviations 60 SD of y 2.5 Summation
  of x2 90. x y are the deviations from their
  arithmetic mean
• A computer while calculating correlation
  coefficient between x y from a pair of 25
  observations. Summation X is 125, Summation X2 is
  650 Summation Y is 100, Summation Y2 is 460
  Summation of XY is 508. Later it is observed
  that two pairs of observations were taken as (6,
  14) and (8,6) instead of (8, 12) and (6,8). Prove
  that the correct correlation coefficient is 0.67.

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• If the relation between two random variables x
  y is 2x3y4, then the correlation coefficient
  is