Question 449994
A spinner that has 3 sections of equal area, numbered from 1 to 3, is spun two times in succession. Which is NOT part of the sample space? (2 points)
(1, 3)
(3, 3)
(3, 2)
(3, 4)
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Ans: (3,4)
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7. A local weather forecaster is accurate 85% of the time when predicting precipitation for the day. What is the probability that she will make correct precipitation predictions 4 days in a row? Round to the nearest whole percent. (2 points)
about 54%
about 53%
about 52%
about 47%
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Ans: 0.85^4 = 52%
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8. A bag contains 6 purple marbles and 7 white marbles. Two marbles are drawn at random. One marble is drawn and not replaced. Then a second marble is drawn. What is the probability that the first marble is white and the second one is purple? (2 points) 
Ans: (7/13)(6/12)
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9. In how many different ways can you arrange 7 books on a shelf? (2 points)
823,543 ways
5,040 ways
720 ways
28 ways
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Ans: 7! = 5040
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Does the problem involve permutations or combination? Explain.
Ans: permutations because it involves counting arrangements, not groups.
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10. In how many different ways could a committee of 5 students be chosen from a class of 25 students?
(2 points)
Permutations; the order matters.
Permutations; the order does not matter.
Combinations; the order does not matter.
Combinations; the order matters.
Ans: combination; the order does not matter
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11. You work at a T-shirt printing business. Of the 2,800 T-shirts shipped, 396 have a defect. What is the experimental probability that a T-shirt has a defect? Write your answer as a percent, to the nearest tenth of a percent. (2 points)
15.3%
14.1%
11.7%
19.4%
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Ans: 396/2800 = 14.1%
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Is the sample described a good sample? Explain.
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12. To find the average income of an adult in the United States, 250 workers in Tennessee are questioned. (2 points)
No; the sample is not random.
Yes; the sample is selected at random from the population to be studied.
No; the sample is not selected from the population to be studied.
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Comment: I'll leave that to you.
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13. A worker takes a random sample of 200 bolts and finds that 30 of them are either too long or too short, thus making them unusable. Estimate the number of unusable bolts in a production of 17,000 bolts. (2 points)
1,610 bolts
2,550 bolts
2, 140 bolts
2,260 bolts
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Ans: (30/200)17000 = 2550
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14. Out of a random sample of 330 apples, 25 are rated "AAA." Estimate the number of apples that would be rated "AAA" in a crop of 57,000 apples. (2 points)
about 432 apples
about 4,318 apples
about 43,180 apples
about 8,636 apples
Ans:(25/33)57000 = 43182 when rounded up
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Cheers,
Stan H.