The Professor's Response

Hi! I am having problems with number 36 from our hw. For the sample variance, I am getting 4,292,520,442 when the answer says it is 429,252,044.2. And so I'm also getting the standard deviation wrong because of that one decimal point off. I don't know if I am putting it wrong in my calculator or what.


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Professor McGukian

Hi Lauren,

The calculation should be done as follows:

There are 21 data values, so n = 21.

The variance will be = (21*15,594,326,388-383,660^2) / (21*20) = 429,252,044.2

If this is the only one of these questions giving you difficulty, it is probably due to the large numbers. You will not face such large numbers on the exam, so I wouldn't worry about it.

Professor McGuckian

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