Question: Weighted standard deviation gives wrong answer?

Okay, I know Maple's not giving the wrong answer...I'm sure I'm just asking the wrong way. When I ask for the standard deviation (Statistics:StandardDeviation) of a list of individual data samples, I get the expected answer. However, when I provide a list of values and a list of frequencies, I don't get the answer I'm expecting. Hopefully the attached worksheet will make my problem obvious. View on MapleNet or Download
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