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Question
Define Correlation.
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Solution
Correlation is a statistical device that helps to analyze the covariation of two or more variables. Sir Francis Galton, is responsible for the calculation of the correlation coefficient.
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In the following data one of the value of y is missing. Arithmetic means of x and y series are 6 and 8 respectively. `(sqrt(2) = 1.4142)`
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| y | 9 | 11 | ? | 8 | 7 |
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| Arithmetic mean | 25 | 18 |
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| Sum of squares of deviation from the arithmetic mean | 136 | 138 |
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| Y | 26 | 35 | 48 | 28 | 20 | 36 | 25 | 40 | 43 | 39 |
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| Y | 17 | 28 | 30 | 32 | 38 | 49 |
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| X | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
| Y | 9 | 8 | 10 | 12 | 11 | 13 | 14 | 16 | 15 |
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