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1 | | In a hypothesis test comparing two population means, the "=" sign always appears in the: |
| | A) | null hypothesis. |
| | B) | alternate hypothesis. |
| | C) | upper tail of the test statistic. |
| | D) | lower tail of the test statistic. |
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2 | | In a hypothesis test comparing two population means, we use the z distribution when: |
| | A) | the two population standard deviations are equal. |
| | B) | both populations have at least 4000 observations. |
| | C) | both population standard deviations are known. |
| | D) | nπ and n(1-π) are both greater than 5. |
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3 | | For the hypothesis, H0: µ1 ≤ µ2, a random sample of 10 observations is selected from the first normal population and 8 from the second normal population. What is the number of degrees of freedom? |
| | A) | 18 |
| | B) | 17 |
| | C) | 16 |
| | D) | 9 |
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4 | | For the hypothesis, H0: µ1 ≤ µ2, (.01 significance level), a random sample of 10 observations is selected from the first normal population and 8 from the second normal population. Population standard deviations are unknown. What is (are) the critical value(s)? |
| | A) | 2.583 |
| | B) | -2.921, 2.921 |
| | C) | -2.583, 2.583 |
| | D) | -2.583 |
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5 | | When testing a hypothesis about the means for two independent populations (population standard deviations unknown), what should be true? |
| | A) | nπ and n(1-π) are both greater than 5. |
| | B) | Both populations are normally distributed. |
| | C) | The samples sizes selected from each population must be equal. |
| | D) | The observations are matched or paired. |
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6 | | To conduct a test of means for two independent populations, which of the following is required? |
| | A) | A z-statistic is used to test the hypothesis. |
| | B) | The population standard deviations must be equal. |
| | C) | nπ and n (1 - π) must be 5 or greater. |
| | D) | A one-tailed hypothesis test. |
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7 | | Another way to state the null hypothesis: H0: µ1 = µ2, is: |
| | A) | H0: µ1 ≤ µ2 |
| | B) | H0: µ1 - µ2 = 0 |
| | C) | H0: µ1 ≥ µ2 |
| | D) | H0: µ1 - µ2 ≠ 0 |
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8 | | To conduct a test of hypothesis for dependent populations, we assume that: |
| | A) | the distribution of the difference between the sampled paired observations follows the normal distribution. |
| | B) | both samples are at least 30. |
| | C) | the samples are unrelated. |
| | D) | nπ and n(1-π) are both greater than 5. |
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9 | | When conducting a test of hypothesis for dependent samples: |
| | A) | the sample size should be at least 30 pairs of observations. |
| | B) | the significance level is more than .05. |
| | C) | the p-value is more than .10. |
| | D) | differences between each matched pair of observations are computed. |
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10 | | Which of the following is necessary to determine a p-value? |
| | A) | Knowledge of whether the test is one-tailed or two-tailed |
| | B) | The value of the test statistic |
| | C) | The level of significance |
| | D) | Both A and B |
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11 | | A z-test statistic of 2.06 was computed to test: H0: µ 1 = µ 2, using a significance level of 0.05. What is the p-value? |
| | A) | 2.0600 |
| | B) | 0.0394 |
| | C) | 0.0197 |
| | D) | 0.4803 |
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12 | | A z-statistic of 1.55 was computed to test H0: µ 1 ≤ µ 2, using a significance level is 0.05. What is the p-value? |
| | A) | 0.0500 |
| | B) | 1.5500 |
| | C) | 0.4394 |
| | D) | 0.0606 |
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13 | | A company is interested in knowing the effects of a computer-training program. The company randomly selected 25 employees and measured their computer skills before and after the training program. To test the hypothesis, H0: µ 1 = µ 2, the populations are: |
| | A) | independent. |
| | B) | dependent. |
| | C) | unrelated. |
| | D) | equal. |
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14 | | A company is interested in knowing the effects of a computer-training program. The company randomly selected 25 employees and measured their computer skills before and after the training program. To test the hypothesis, H0: µ 1 = µ 2, the test statistic is a: |
| | A) | z-statistic. |
| | B) | t-statistic with 49 degrees of freedom. |
| | C) | t-statistic with 23 degrees of freedom. |
| | D) | chi-square statistic with 23 degrees of freedom. |
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