If every value of X is multiplied by 5 and every value of Y is multiplied by 2, the correlation coefficient will:
Correct answer: C. Remain unchanged
- A. Be multiplied by 10
- B. Be divided by 10
- C. Remain unchanged
- D. Become equal to zero
Explanation
Positive changes of measurement scale do not alter the direction or strength of linear association. The covariance and standard deviations change proportionally, so their ratio remains the same.
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About Correlation and Regression
Correlation describes the direction and strength of association between two variables using scatter diagrams and correlation coefficients. Regression covers fitted lines, regression equations, prediction and least squares, with a clear distinction between association and causation and between estimating a response value and reversing the roles of the variables.
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