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Quarters Don’t Compare

Calendar quarters are not really comparable

Fortune’s CNN Money takes a closer look at Mac sales and discovers that what appears to be a decline is actually the opposite  Wall Street forecasters are projecting a quarter-on-quarter decline in Mac sales for Q1 2013. This looks bad for Apple, but a closer look reveals that it really isn’t so.

MacUnitSalesByQuarters

Taking these numbers at face value does not take into account that Q1 last year had 14 weeks, not the usual 13. Adjusting for the number of weeks in the quarter produces a increase in sales from 5 to 10 percent — a big difference in conclusion.

So when comparing quarters, be sure that you are comparing apples to apples.

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