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Unformatted text preview: 11-12-07 Hypothesis Testing Suppose a fabric manufacturer has received many complaints about the toughness of the material. 1000 MD strength. Suppose you take a sample and find 1010 MD strength. A second sample yields XBAR = 995 We ned to test a hypothesis as a point estimate would not. Null vs. Alternative Hypothesis HO = Null Hypothesis HA = Alternative Hypothesis HO = 1000lb/Ream = True Mean HA = 1000lb/Ream = True Mean The Rejection Region is called the level of significance: z = 1.96 z = -1.96 11-26-07 Two Tails One Tail Test of the Mean Small Sample: We must want to know if the mean has shifted in one direction. In that case, we conduct a one tail test of . The case of the fabric company, we might want to know if the resistance of the material has decreasedfrom 1000lb/Ream. In this case, we will use a lower tail test. Since the tissue company wants to know whether or not <1000lb/Ream This must go into the alternative hypothesis: ...
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This note was uploaded on 04/18/2008 for the course ECON 205 taught by Professor Diagne during the Fall '07 term at Towson.
- Fall '07