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

AP.STATS: UNC‑4 (EU), UNC‑4.C (LO), UNC‑4.C.1 (EK), UNC‑4.C.2 (EK), UNC‑4.C.3 (EK), UNC‑4.C.4 (EK), UNC‑4.H (LO), UNC‑4.H.1 (EK), UNC‑4.H.2 (EK)
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## Problem

Jonah wants to make a one-sample z interval using 99, percent 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, percent. A previous study suggests that about 6, percent of these wafers are defective.
If we assume p, with, hat, on top, equals, 0, point, 06, what is the smallest sample size required to obtain the desired margin of error?