Unformatted text preview: it be left
tail or right
tail? Why? PROBLEM # 8.6 In hypothesis testing, what is meant by the decision rule? What role does it play in the hypothesis testing procedure? PROBLEM # 8.7 What is the central limit theorem, and how is it applicable to hypothesis testing? PROBLEM # 8.8 If the population standard deviation is known, but the sample size is less than 30, what assumption is necessary to use the z
statistic in carrying out a hypothesis test for the population mean? 2 PROBLEM # 8.9 For a sample of 35 items from a population for which the standard deviation is ! =20.5, the sample mean is 458.0. At the 0.05 level of significance, test H0:! = 450 versus H1:! ≠450. Determine and interpret the p
value for the test. 1. Set up hypotheses: H0: H1: Level of significance: α = 2. What is the appropriate test statistic to use? 3. Calculate the test statistics value 4. Find the critical value for the test statistic 5. Define your decision rule: 6. Make your decision: 7. Interpret the conclusion in context: 1
2
3
4
5
6
7 A
zTest of a Mean
Sample mean
Population standard deviation
Sample size
Hypothesized mean
Alpha B 458.0
20.5
35
450
0.05 C z Stat
P(Z<=z) onetail
z Critical onetail
P(Z<=z) twotail
z Critical twotail D 2.31
0.0105
1.645
0.0210
1.960 3 PROBLEM # 8.10 For each of the following tests and z
values, determine the p
value for the test: a. Right
tail test and z=1.54 b. Left
tail test and z=
1.03 c. Two
tail test and z=1.27 PROBLEM # 8.11 For a sample of 12 items from a normally distributed population for which the standard deviation is ! =17.0, the sample mean is 230.8. At the 0.05 level of significance, test H0:! ≤ 220 versus H1:! >220. Determine and interpret the p
value for the test. 1. Set up hypotheses: H0: H1: Level of significance: α = 2. What is the appropriate test statistic to use? 3. Calculate the test statistics value 4. Find the critical value for the test statistic 5. Define your decision rule: 6. Make your decision: 7. Interpret the conclusion in context: 4 PROBLEM # 8.12 In the past, patrons of a cinema complex have spent an average of $5.00 for popcorn and other snacks, with a standard deviation of $1.80. The amounts of these expenditures have been normally distributed. Following an intensive publicity campaign by a local medical society, the mean expenditure for a sample of 18 patrons is found to be $4.20. In a one
tail test at the 0.05 level o...
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 Fall '08
 GHATRI
 Standard Deviation, the00, Engineer00

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