A process is considered to be performing acceptably if its mean is 200. Because it is expensive to shut down and reconfigure this process, such measures are undertaken only if there is compelling evidence that the process mean is not 200. Experience has shown that the process is normally distributed with a standard deviation if 40.
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| 4 | |
What is an appropriate alternate hypothesis in this setting? |
| | A) | H1: μ = 200 |
| | B) | H1: μ ≠ 200 |
| | C) | H1: μ ≥ 200 |
| | D) | H1: μ ≤ 200 |
| | E) | None of the above |
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| 5 | |
In this situation, a Type I error would be made when it is concluded that μ is _______ 200 when in fact μ _______ 200. |
| | A) | Greater than; less than or equal to |
| | B) | Less than; greater than or equal to |
| | C) | Equal to; greater than |
| | D) | Not equal to; equals |
| | E) | Equals; not equal to |
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| 6 | |
Suppose in a random sample of size n = 16 a sample average of 185 is observed. The p-value of this sample statistic is: |
| | A) | 0.0668 |
| | B) | 0.1336 |
| | C) | 0.3520 |
| | D) | 0.7039 |
| | E) | None of the above |
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| 7 | |
When conducting a test about the population mean with sample size 15, using sample mean and sample standard deviation, the test statistic is: |
| | A) | z-value |
| | B) | t-value with df = n. |
| | C) | t-value with df = n + 1. |
| | D) | t-value with df = n - 1. |
| | E) | none of the above |
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| 8 | |
For a given hypothesis test, the p-value of the test statistic equals 0.032. This implies a 0.032 probability of making a |
| | A) | Type I error |
| | B) | Type II error |
| | C) | Type I result |
| | D) | Type II result |
| | E) | None of the above |
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| 9 | |
In a two-tailed hypothesis test involving a normally distributed population parameter with a known standard deviation, the computed test statistic was Z = 1.74. If the null hypothesis is rejected based on this evidence, the risk of making a __________ error is approximately ___________. |
| | A) | Type I; 4.1 % |
| | B) | Type II; 4.1% |
| | C) | Type I; 8.2% |
| | D) | Type II; 8.2% |
| | E) | None of the above |
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| 10 | |
In a left-tailed hypothesis test involving a normally distributed population with a known standard deviation, the computed test statistic was Z = −1.74. If the null hypothesis is rejected based on this evidence, the risk of making a __________ error is approximately ___________. |
| | A) | Type I; 4.1 % |
| | B) | Type II; 4.1% |
| | C) | Type I; 95.9% |
| | D) | Type II; 95.9% |
| | E) | Both A and D are correct |
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| 11 | |
Conduct a test to determine whether or not the population proportion of voters in favor of proposal A is greater than 50%. In a random sample of 200 voters, 140 said that they were in favor of this proposal. Compute the test statistic. |
| | A) | z = 6.17 |
| | B) | z = 19.80 |
| | C) | z = 5.66 |
| | D) | z = 7.07 |
| | E) | none of the above |
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| 12 | |
A quality improvement consultant has promised that his techniques will reduce variance in a particular process. Prior to implementation, the variance in this process was 28. A random sample of 80 observations drawn from this process exhibited a sample variance of 22. If alpha was set at 0.05, a test of H0: σ2 ≥ 28 would imply that the consultant's techniques ________________ process variance. |
| | A) | Reduced |
| | B) | Increased |
| | C) | Didn't change |
| | D) | Multiplied |
| | E) | None of the above |
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