GRE
The standard deviation of the numbers 45, 64, 83, and 53
The standard deviation of the numbers 55, 81, 47, and 62
$$\frac{100!}{99!}$$
$$\frac{ (100!-99!)}{98!}$$
$$\frac{(5!+6!)}{(6!+7!)}$$
$$\frac{1}{6}$$
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