chapter 7 questions

# chapter 7 questions - For a given hypothesis test if we do...

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For a given hypothesis test, if we do not reject H 0 , and H 0 is true.

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Your Answer: Choice Selected Correct Type I error has been committed. No error has been committed. Type III error has been committed. Type II error has been committed. Question 2: Score 0/1 The manager of the quality department for a tire manufacturing company wants to know the average tensile strength of rubber used in making a certain brand of radial tire. The population is normally distributed and the population standard deviation is known. She uses a Z test to test the null hypothesis that the mean tensile strength is less than or equal to 800 pounds per square inch. The calculated Z test statistic is a positive value that leads to a p-value of .067 for the test. Reference: 08_01 If the significance level is .05, the null hypothesis would be rejected. Your Answer: Choice Selected Correct True False Question 3: Score 0/1 In forming a large sample confidence interval for , two assumptions are required: independent samples and sample sizes of at least 30.
Your Answer: Choice Selected Correct True False Question 4: Score 0/1 In order to test the effectiveness of a drug called XZR designed to reduce cholesterol levels, 9 heart patients' cholesterol levels are measured before they are given the drug. The same 9 patients use XZR for two continuous months. After two months of continuous use the 9 patients' cholesterol levels are measured again. The comparison of cholesterol levels before vs. after administering the drug is an example of testing the difference between: Your Answer: Choice Selected Two population proportions. Matched pairs from two dependent populations. Two means from independent populations. Two population variances from independent populations. Exercise 8.29 We consider using a random sample of 49 measurements to test H 0 : µ = 20 versus H a : µ < 20. If = 15.5 and σ = 7, calculate the value of the test statistic z . How much evidence is there that H 0 : µ = 20 is false and H a : µ 20 is true? Round answers to 4 decimal places. Since p -value = 0 with a tolerance of ±0.004 is less than .05, there is strong evidence.

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Recall that the television network will permit National Motors to claim that the ZX-900 achieves a shorter mean stopping distance than a competitor if H 0 : µ > 60 can be rejected in favor of H 1 : µ < 60 by setting α equal to .05. If the stopping distances of a random sample of n = 81 ZX-900s have a mean of = 56.6 ft, will National Motors be allowed to run the commercial? Assume here that σ = 6.22 . Calculate a 95 percent confidence interval for µ. Do the point estimate of µ and confidence interval for µ indicate that µ might be far enough below 60 feet to suggest that we have a practically important result? Round answers to 2 decimal places. Round confidence interval to 3 decimal places. A
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chapter 7 questions - For a given hypothesis test if we do...

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