The weight of a certain type of brick has an expectation of 1.12kg with a standard deviation of .03kg.
Find: expectation and variance given 25 randomly selected bricks, and number of bricks necessary to have a standard deviation of .005 or less.
I know expectation is 1.12kg, and I know two formulas for variance, but neither of those are applicable here. What's the formula to use?
And for the other part of the question, I understand why there's a certain number, but short of trial and error I can't think of a way to actually calculate it. Tips?
2006-09-04
16:51:45
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1 answers
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asked by
Anonymous
3
in
Mathematics