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A researcher wishes to test whether a particular diet has an effect on blood pressure. The blood pressure of 25 randomly selected adults is measured. After one month on the diet, each person's blood pressure is again measured. For 15 people, the second blood pressure reading was lower than the first, and for 10 people, the second blood pressure reading was higher than the first. At the 0.01 significance level, test the claim that the diet has an effect on blood pressure.
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| Conclusion: The diet does not appear to have an effect on blood pressure. |
| Conclusion: There is sufficient evidence to reject the null hypothesis. |
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A researcher wishes to study whether music has any effect on the ability to memorize information. 84 randomly selected adults are given a memory test in a quiet room. They are then given a second memory test while listening to classical music. 70 people received a higher score on the second test, 13 a lower score, and 1 received the same score. At the 0.05 significance level, test the claim that the music has no effect on memorization skills.
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| There is sufficient evidence to warrent rejection of the null hypothesis that music has no effect on memorization skills. |
| Accept the null hypothesis. |
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| There is insufficient evidence to conclude that the diet has an effect on systolic blood pressure. |
| Reject the null and accept the claim that the diet does have an effect on systolic blood pressure. |
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| Conclusion: the times for the two routes have the same distribution. |
| Conclusion: the times for two routes do not have the same distribution. |
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| There is sufficient evidence to accept the claim that the bulbs come from different populations. |
| Accept the null. |
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Given that the rank correlation coefficient, rs, for 20 pairs of data is 0.723, test the claim of no correlation between the two variables. Use a significance level of 0.05.
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| There appears to be a correlation. |
| There does not appear to be a correlation. |
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A true-false test had the following answer sequence. T T T T F T F T F T F T T F T
T T F F F F F F F T F T F T F Test the null hypothesis that the sequence was random.
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| The sequence appears to be random. |
| Reject the null. |
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| Accept the null. |
| Accept the alternative. |