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I got this one wrong and only have one try remaining. I said B on my attempt. If

ID: 3302179 • Letter: I

Question

I got this one wrong and only have one try remaining. I said B on my attempt. If possible please just very briefly explain why this isn't correct :)

Describe the sample variance using words rather than a formula. Do the same with the population variance. Choose the correct answer below.

A.

The sample variance is the sum of the deviations from the mean divided by the number of measurements minus one. The population variance is the average of the distances of the measurements on all units in the population from the mean.

B.

The sample variance is the sum of the squared deviations from the mean divided by the number of measurements. The population variance is the sum of the squared deviations from the mean divided by the number of measurements minus one.

C.

The sample variance is the sum of the deviations from the mean divided by the number of measurements. The population variance is the sum of the deviations from the mean divided by the number of measurements minus one.

D.

The sample variance is the sum of the squared deviations from the mean divided by the number of measurements minus one. The population variance is the average of the squared distances of the measurements on all units in the population from the mean.

Explanation / Answer

The correct answer is

D. The sample variance is the sum of the squared deviations from the mean divided by the number of measurements minus one. The population variance is the average of the squared distances of the measurements on all units in the population from the mean.

Both the sample variance and the population variance make use of squared distances or deviations. The difference is that while population variance divides it by the number of measurements (average), sample variance divides it by number of measurements minus one.