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| 1 | |
The null hypothesis |
| | A) | Is a statement about the value of the population parameter. |
| | B) | Will always contain the equal sign. |
| | C) | Cannot include values less than 0. |
| | D) | Both a and b are correct. |
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| 2 | |
The alternate hypothesis |
| | A) | Is accepted if the null hypothesis is rejected. |
| | B) | Will always contain the equal sign. |
| | C) | Tells the value of the sample mean. |
| | D) | None of the above. |
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| 3 | |
The level of significance |
| | A) | Is frequently .05 or .01. |
| | B) | Can be any value between 0 and 1. |
| | C) | Is the likelihood of rejecting the null hypothesis when it is true. |
| | D) | All of the above. |
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| 4 | |
A Type I error is |
| | A) | The correct decision. |
| | B) | A value determined from the test statistic. |
| | C) | Rejecting the null hypothesis when it is true. |
| | D) | Accepting the null hypothesis when it is false. |
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| 5 | |
The critical value is |
| | A) | Calculated from sample information. |
| | B) | Cannot be negative. |
| | C) | The point that divides the acceptance region from the rejection region. |
| | D) | A value determined from the test statistic. |
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| 6 | |
In a one-tailed test |
| | A) | The rejection region is in one of the tails. |
| | B) | The rejection region is split between the tails. |
| | C) | The p-value is always less than the significance level. |
| | D) | The p-value is always more than the significance level. |
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| 7 | |
To conduct a one sample test of means and use the z distribution as the test statistic |
| | A) | We need to know the population standard deviation. |
| | B) | We can use the sample standard deviation provided n is at least 30. |
| | C) | We need np to be at least 5. |
| | D) | Both A and B are correct. |
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| 8 | |
The p-value is |
| | A) | The same as the population proportion. |
| | B) | The same as the significance level. |
| | C) | The fraction of the population that has a particular characteristic. |
| | D) | The probability of finding a value of the test statistic this extreme when the null hypothesis is true. |
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| 9 | |
Which of the following statements are correct when deciding whether to use the z or the t distribution? |
| | A) | Use z when the sample size is 30 or more. |
| | B) | Use z when we have a normal population and know the standard deviation. |
| | C) | Use t when the population is normal, the population standard deviation is not known, and n is less than 30. |
| | D) | All of the above statements are correct. |
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| 10 | |
The mean length of a long-distance call, based on information gathered over the last several years, is 12.5 minutes. A new rate plan was introduced last month. A sample of 20 calls this month showed the mean increased to 13.0 minutes. The standard deviation of the sample was 0.60 minutes. At the .05 significance level can we conclude that the mean call length has increased? Which of the following is a correct statement of the null and alternate hypothesis? |
| | A) | H0: μ = 12.5 H1: μ > 12.5 |
| | B) | H0: μ = 13 H1: μ > 13 |
| | C) | H0: μ < 12.5 H1: μ = 12.5 |
| | D) | H0: μ = 12.5 H1: μ < 12.5 |
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| 11 | |
The mean length of a long-distance call, based on information gathered over the last several years, is 12.5 minutes. A new rate plan was introduced last month. A sample of 20 calls this month showed the mean increased to 13.0 minutes. The standard deviation of the sample was 0.60 minutes. At the .05 significance level can we conclude that the mean call length has increased? Which of the following is the appropriate decision rule? |
| | A) | Reject H0 if z > 1.65. |
| | B) | Reject H0 if t > 1.729. |
| | C) | Reject H0 if t < -2.093 or t > 2.093. |
| | D) | Reject H0 if t > 1.725. |
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| 12 | |
The mean length of a long-distance call, based on information gathered over the last several years, is 12.5 minutes. A new rate plan was introduced last month. A sample of 20 calls this month showed the mean increased to 13.0 minutes. The standard deviation of the sample was 0.60 minutes. At the .05 significance level can we conclude that the mean call length has increased? Determine the value of the test statistic and state your decision regarding the null hypothesis. |
| | A) | t = 3.727, reject H0. |
| | B) | z = 3.727, reject H0. |
| | C) | t = 3.727, do not reject H0. |
| | D) | None of the above. |
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| 13 | |
The mean length of a long-distance call, based on information gathered over the last several years, is 12.5 minutes. A new rate plan was introduced last month. A sample of 20 calls this month showed the mean increased to 13.0 minutes. The standard deviation of the sample was 0.60 minutes. At the .05 significance level, what can we conclude about the mean call length? |
| | A) | The mean length of the calls has not changed. |
| | B) | The mean length of calls decreased. |
| | C) | The mean length of calls increased. |
| | D) | None of the above. |
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| 14 | |
The resting heart rate of sedentary office workers was found to be 84 beats per minute. A sample of 36 were put on an exercise and diet program and at the end of it, were found to have a rate of 82 with a standard deviation of 6. We want to determine whether the program has decreased the heart rate. What is the appropriate decision rule at the .05 level of significance? |
| | A) | Reject if z < -1.645 |
| | B) | Reject if z < 1.645 |
| | C) | Reject if z < -1.96 |
| | D) | Reject if t < -.697 |
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| 15 | |
The resting heart rate of sedentary office workers was found to be 84 beats per minute. A sample of 36 were put on an exercise and diet program and at the end of it, were found to have a rate of 82 with a standard deviation of 6. We want to determine whether the program has decreased the heart rate. What can we conclude at the .05 level of significance? |
| | A) | The program has decreased the heart rate. |
| | B) | The program has had no effect on the heart rate. |
| | C) | The program has increased the heart rate. |
| | D) | The test is inconclusive because the sample is too small. |
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