Question
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The sum and the sum of squares of the observations corresponding to length X (in cm) and weight Y (in gm) of 50 tropical tubers are given as \(\Sigma X = 200$, \Sigma Y = 250, \Sigma X^2 = 900 and \Sigma Y^2 = 1400\)
Which one of the following is correct?
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFCalculation:
Given,
The sum and sum of squares of the observations corresponding to length X in cm and weight Y in gm of 50 tropical tubers are given as:
\(\Sigma X\) = 200, \(\Sigma Y\) = 250, \(\Sigma X^2\)= 900, \(\Sigma Y^2\) = 1400
The formula for variance is:
\( \text{Variance} = \frac{\Sigma X^2}{N} - \left( \frac{\Sigma X}{N} \right)^2 \)
Where N = 50 is the number of observations.
Variance of X:
\( \text{Variance of } X = \frac{\Sigma X^2}{N} - \left( \frac{\Sigma X}{N} \right)^2 \)
Substituting the given values:
\( \text{Variance of } X = \frac{900}{50} - \left( \frac{200}{50} \right)^2 \)
\( \text{Variance of } X = 18 - 16 = 2 \)
Variance of Y:
\( \text{Variance of } Y = \frac{\Sigma Y^2}{N} - \left( \frac{\Sigma Y}{N} \right)^2 \)
Substituting the given values:
\( \text{Variance of } Y = \frac{1400}{50} - \left( \frac{250}{50} \right)^2 \)
\( \text{Variance of } Y = 28 - 25 = 3 \)
Conclusion:
\( \text{Variance of } X < \text{Variance of } Y \)
Hence, the correct answer is Option 2.
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