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Unformatted text preview: 1 CHAPTER 11: INTRO TO HYPOTHESIS TESTING Stats & Prob. for Bus. Mgmt (Stat1100) Jochem Chap 11: Intro to Hypothesis Testing b Goals of Chapter 11 b 1. How to test hypotheses. b 2. Differentiate between and compute type 1 and type 2 errors. 2 b 3. Explain why a larger sample allows for more reliable decisionmaking. b 1. Hypothesis Testing b Besides estimation (as in Chap 10), hypothesis testing is another form of inference. ference = deriving conclusions from information/data. 3 Chap 11: Intro to Hypothesis Testing s Inference = deriving conclusions from information/data. b Hypothesis testing is to evaluate a claim about the population. It uses data from a sample to determine if there is sufficient evidence to refute the claim. b 1. Hypothesis Testing b Example 1: s Claim: The average time a Pitt student studies per day (outside of classes) is 90 minutes* B H : μ =90 min 4 Chap 11: Intro to Hypothesis Testing (outside of classes) is 90 minutes* B H : μ =90 min s Sample of 11 Pitt students (STAT 1000): B xbar=147 min *Suppose σ =90 & normally distr. b 1. Hypothesis Testing b Example 1: s Claim: The average time a Pitt student studies per day (outside of classes) is 90 minutes* B H : μ =90 min 5 Chap 11: Intro to Hypothesis Testing (outside of classes) is 90 minutes* B H : μ =90 min s Sample of 11 Pitt students (STAT 1000): B xbar=147 min μ = 90 min xbar= 147 min Std dev= σ/sqrt(n) = 27 min Hypothesis Testing asks the Question: What is the probability that we would find a sample with mean 147 min ASSUMING THAT THE CLAIM IS TRUE? *Suppose σ =90 & normally distr. b 1. Hypothesis Testing b Example 1: s Claim: The average time a Pitt student studies per day (outside of classes) is 90 minutes* B H : μ =90 min 6 Chap 11: Intro to Hypothesis Testing (outside of classes) is 90 minutes* B H : μ =90 min s Sample of 11 Pitt students (STAT 1000): B xbar=147 min μ = 90 min xbar= 147 min Std dev= σ/sqrt(n) = 27 min *Suppose σ =90 & normally distr. b 1. Hypothesis Testing b Example 1: s Claim: The average time a Pitt student studies per day (outside of classes) is 90 minutes* B H : μ =90 min 7 Chap 11: Intro to Hypothesis Testing (outside of classes) is 90 minutes* B H : μ =90 min s Sample of 11 Pitt students (STAT 1000): B xbar=147 min μ = 90 min xbar= 147 min Std dev= σ/sqrt(n) = 27 min 1.74% is called the “P VALUE ”: it is the probability that a sample mean of 147 min (or more extreme) occurs IF the claim was true. Pvalues… h 10% = not sufficient evidence/not significant 510% = weak evidence/weakly significant 15% = strong evidence/strongly significant < 1% = overwhelming evidence/highly significant *Suppose σ =90 & normally distr....
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This note was uploaded on 03/26/2012 for the course STAT 1100 taught by Professor Chiappetta during the Spring '08 term at Pittsburgh.
 Spring '08
 Chiappetta

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