Coefficient of correlation...ppt
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The document defines and describes the coefficient of correlation, which is a statistic that measures the strength and direction of the linear relationship between two variables on a scale of -1 to +1. It explains that a correlation of -1 is a perfect negative correlation, 0 is no correlation, and +1 is a perfect positive correlation. The document also differentiates between types of correlation coefficients and methods for computing correlation coefficients, including Karl Pearson's and Spearman's rank correlation coefficients.
Coefficient of correlation...ppt
- 2. A statistic representing how closely two variables co-vary; it can vary from -1 (perfect negative correlation) through 0 (no correlation) to +1 (perfect positive correlation).
- 3. • The correlation coefficient, denoted by r, is a measure of the strength of the straight-line or linear relationship between two variables. The correlation coefficient takes on values ranging between +1 and -1. • The quantity r, called the linear correlation coefficient, measures the strength and the direction of a linear relationship between two variables
- 4. Type of correlation coefficient 1. Perfect Positive correlation 2. Perfect negative correlation 3. Moderately Positive correlation 4. Moderate negative correlation 5. Absolute no correlation
- 5. Perfect Positive correlation • If x and y have a strong positive linear correlation, r is close to +1. An r value of exactly +1 indicates a perfect positive fit. Positive values indicate a relationship between x and y variables such that as values for x increases, values for y also increase.
- 7. Perfect negative correlation • If x and y have a strong negative linear correlation, r is close to -1. An r value of exactly -1 indicates a perfect negative fit. Negative values indicate a relationship between x and y such that as values for x increase, values for y decrease.
- 9. Moderately Positive correlation • 0<r<1 Moderate negative correlation -1<r<1
- 13. Absolute no correlation • If there is no linear correlation or a weak linear correlation, r is close to 0. A value near zero means that there is a random, nonlinear relationship between the two variables
- 14. Methods of computing the correlation • karl pearson’s correlation coefficient • spearman’s rank correlation coefficient