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Question 1
1. Based on the Nielsen ratings, the local CBS affiliate claims its 11:00 PM newscast reaches 41% of the viewing audience in the area. In a survey of 100 viewers, 36% indicated that they watch the late evening news on this local CBS station. What is your decision if α = 0.01?
Answer
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Fail to reject the null hypothesis and conclude the newscast reaches about 41% of the audience. |
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Reject the null hypothesis and conclude the newscast does not reach 41% of the audience. |
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Fail to reject the alternate and conclude the newscast does not reach 41% of the audience. |
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Reject the alternate and conclude the newscast reaches about 41% of the audience. |
20 points
Question 2
1. A manufacturer wants to increase the absorption capacity of a sponge. Based on past data, the average sponge could absorb 3.5 ounces. After the redesign, the absorption amounts of a sample of sponges were (in ounces): 4.1, 3.7, 3.3, 3.5, 3.8, 3.9, 3.6, 3.8, 4.0, and 3.9. What is the decision rule at the 0.01 level of significance to test if the new design increased the absorption amount of the sponge?
Answer
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Do not reject null hypothesis if computed t is less than 2.580 |
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Do not reject null hypothesis if computed t is less than 2.821 |
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Reject null hypothesis if computed z is 1.96 or larger |
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Reject null hypothesis if computed t is less than 2.764 |
20 points
Question 3
1. It is claimed that in a bushel of peaches less than ten percent are defective. A sample of 400 peaches is examined and 50 are found to be defective. What is the p-value?
Answer
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0.0250 |
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0.4525 |
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0.0475 |
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0.0500 |
20 points
Question 4
1. A hypothesis regarding the weight of newborn infants at a community hospital is that the mean is 6.6 pounds. A sample of seven infants is randomly selected and their weights at birth are recorded as 9.0, 7.3, 6.0, 8.8, 6.8, 8.4, and 6.6 pounds. What is the decision for a significant increase in the average birthrate at a 5% level of significance?
Answer
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Fail to reject the null hypothesis and conclude the mean is 6.6 lb. |
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Reject the null hypothesis and conclude the mean is lower than 6.6 lb. |
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Reject the null hypothesis and conclude the mean is greater than 6.6 lb. |
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Cannot calculate because population standard deviation is unknown. |
20 points
Question 5
1. A hypothesis regarding the weight of newborn infants at a community hospital is that the mean is 6.6 pounds. A sample of seven infants is randomly selected and their weights at birth are recorded as 9.0, 7.3, 6.0, 8.8, 6.8, 8.4, and 6.6 pounds. If α = 0.05, what is the critical t value?
Answer
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-2.365 |
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±1.96 |
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±2.365 |
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±2.447 |
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-2.447 |
