GK
BUSINESS ECONOMICS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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exactly same
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totally different
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similar except for (n-1) in the denominator instead of N
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similar except for (n + 1) in the denominator instead of N
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Detailed explanation-1: -WHY DOES THE SAMPLE VARIANCE HAVE N-1 IN THE DENOMINATOR? The reason we use n-1 rather than n is so that the sample variance will be what is called an unbiased estimator of the population variance 2.
Detailed explanation-2: -The Sample Variance is always more than the Population Variance, reason being, for samples, the size is sometimes much less than the population and that accounts for errors due to lack of information and hence the spread is more.
Detailed explanation-3: -The variance of the sum would be 2 + 2 + 2. For N numbers, the variance would be N2. Since the mean is 1/N times the sum, the variance of the sampling distribution of the mean would be 1/N2 times the variance of the sum, which equals 2/N.