Probability Models Quiz 8 (25 MCQs)

Quiz Instructions

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1. Which scenario represents a uniform probability model?
2. Which of the following represents a simulation of drawing a card from a deck?
3. What tool is best used to represent all outcomes of flipping two coins?
4. A computer chip company manufacturer rejects 2% of the chips produced because they fail presale testing. How many do you expect to test before finding a bad one?
5. The Gallup Poll asked a random sample of 1785 adults whether they attended church during the past week. Let p-hat be the proportion of people in the sample who attended church. A newspaper report claims that 40% of all U.S. adults went to church last week. Suppose this claim is true. Calculate the standard deviation of the sampling distribution.
6. Given that families continue to have children until they get a girl, what is the expected number of children per family? Standard deviation?
7. Which of the following is FALSE about binomial probabilities?
8. Find the probability of achieving success with the event:Rolling a die twice in a row and getting two threes.
9. A marksman has 80% accuracy hitting targets at 1, 000 yards. What is the probability that he will make exactly 18 of his next 20 shots?
10. The mean and standard deviation of a population are 400 and 40, respectively. Sample size is 25. What is the mean of the sampling distribution?
11. How is uniform probability used in statistics?
12. A model predicts that a fair coin will land heads up 50% of the time. If you flip the coin 100 times and get 48 heads, is this result consistent with the model?
13. About 12% of children are believed to have nearsightedness. A school tests the vision of 169 kindergarten students. How many do you expect to be nearsighted?
14. Clara picks a card at random, puts it back, and then picks another card at random.
15. A number cube is weighted so that the faces 1, 2, or 3 are all twice as likely to occur as each of the faces labeled 4, 5, or 6. What statements must you add to P(1)=2/9, P(2)=2/9, P(3)=2/9 to make a complete probability model?
16. Which of the following expressions can be used to calculate the probability of two related events occurring?
17. In 2010, an Angus Reid Public Opinion poll found that 56% of all Canadians admit to regularly swearing when they converse with friends (46% for Americans). A researcher plans to select a random sample of 200 Canadians from Montreal to further survey them about this topic. Verify that a Normal model is a useful approximation for the Binomial in this situation.
18. Matilda is spinning a spinner with eight equal-sized sections numbered 1 through 8. She spins the spinner two times. What is the probability that Matilda's first spin will be an odd number and her second spin will be a number less than 3?
19. If you flip a coin three times, what is the probability of getting heads all three times?
20. For college students, 30% are enrolled in math, 55% are enrolled in English, and 14% are enrolled in both. If a student is selected at random, find the probability that the student is enrolled in either mathematics or English, but not both.
21. 60% of the commercials aired on a network from 8 PM to 10 PM are 15 seconds long, 20% are 30 seconds long, and the rest are 60 seconds. What is the standard deviation?
22. Sandra spins the pointer of a spinner. The spinner has four equal sections labeled 1 to 4. What is the probability that the pointer will land on a number less than 5?
23. What is the probability of an event that cannot happen?
24. What is the sum of the probabilities of all possible outcomes of an event?
25. A computer chip manufacturer rejects 2% of the chips produced because they fail presale testing. If you have a random sample of 400 chips, what is the mean number of chips you expect to fail?