Dear members,(adsbygoogle = window.adsbygoogle || []).push({});

here is a gre problem that I couldn't know how to tackle, any effort will be greatly appreciated.

An experimenter measures 9934 counts during one hour from a radioactive sample. From this number the counting rate of the sample can be estimated with a standard deviation of most nearly

(A) 100

(B) 200

(C) 300

(D) 400

(E) 500

the answer is (A) 100, could anyone please help me out understand this problem

thanks so much!

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# Gre Problem # 40

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