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Sample size and margin of error in a z interval for p

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Jonah wants to make a one-sample z interval using 99% confidence to estimate what proportion of silicon wafers at his factory are defective. He wants the margin of error to be no more than 3%. A previous study suggests that about 6% of these wafers are defective.
If we assume p^=0.06, what is the smallest sample size required to obtain the desired margin of error?
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