Friday, December 10, 2010

negative t-stat?

We calculate the t stat by subtracting the hypothesised mean from the sample mean, and then dividing by the standard error. Now it can happen that the hypothesised mean is larger than the sample mean. The result is that the t stat is negative. That is OK. But when you put it into Excel, just type the t stat as an absolute value (that means drop the negative sign).

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