STAT 230 2nd Quiz

1. The National Center for Health Statistics reported that of every 883 deaths in recent years, 24 resulted from an automobile accident, 182 from cancer and 333 from heart disease. What is the probability that a particular death is due to an automobile accident? A. 24/883 or 0.027 B. 539/883 or 0.610 C. 24/333 or 0.072 D. 182/883 or 0.206

2. What does the complement rule state? A. B. C. D.

3. A firm offers routine physical examinations as part of a health service program for its employees. The exams showed that 8% of the employees needed corrective shoes, 15% needed major dental work and 3% needed both corrective shoes and major dental work. What is the probability that an employee selected at random will need either corrective shoes or major dental work? A. 0.20 B. 0.25 C. 0.50 D. 1.00

4. The first card selected from a standard 52-card deck was a king. If it is returned to the deck, what is the probability that a king will be drawn on the second selection? A. 1/4 or 0.25 B. 1/13 or 0.077 C. 12/13 or 0.923 D. 1/3 or 0.33

5. What does equal? A. 640 B. 36 C. 10 D. 120

6. How many permutations of the two letters C and D are possible? A. 1 B. 0 C. 2 D. 8

7. A builder has agreed NOT to build all "look alike" homes in a new subdivision. The builder has 3 different interior plans that can be combined with any of the 5 different home exteriors. How many different homes can be built? A. 8 B. 10 C. 15 D. 30

8. A lamp manufacturer has developed 5 lamp bases and 4 lampshades that could be used together. How many different arrangements of base and shade can be offered? A. 5 B. 10 C. 15 D. 20

9. If the variance is 3.6 grams, what is the standard deviation? A. 0.6 B. 1.897 C. 6.0 D. 12.96

10. Which of the following is correct about a probability distribution? A. Sum of all possible outcomes must equal 1 B. Outcomes must be mutually exclusive C. Probability of each outcome must be between 0 and 1 inclusive D. All of the above

11. A study of 200 computer service firms revealed these incomes after taxes: What is the probability that a particular firm selected has $1 million or more in income after taxes? A. 0.00 B. 0.25 C. 0.49 D. 0.51

12. For the following probability distribution, the mean is A. 12 B. 0.2 C. 0 D. 10

13. The probabilities and the number of automobiles lined up at a Lakeside Olds at opening time (7:30 a.m.) for service are On a typical day, how many automobiles should Lakeside Olds expect to be lined up at opening? Hint. A. 10.00 B. 1.00 C. 2.85 D. 1.96

14. The following is a binomial probability distribution with n = 3 and π = 0.20. The variance of the distribution is (Hint ) A. 1.5 B. 3.0 C. 0.69 D. 0.48

15. There are 8 flights from Minneapolis to St. Cloud each day. The probability that any one flight is late is 0.10. Using the binomial probability formula, what is the probability that exactly 1 flight is late? Hint: . A. 0.048 B. 0.383 C. 0.00000072 D. 0.627

16. Which one of the following is NOT a condition of the binomial distribution? A. Independent trials B. Only two outcomes C. Probability of success remains constant from trial to trial D. At least 10 observations

17. Chances are 50-50 that a newborn baby will be a girl. For families with five children, what is the probability that all the children are girls? A. 0.900 B. 0.031 C. 0.001 D. 0.250

18. The standard normal distribution is a special normal distribution with a mean of 0 and a standard deviation of 1. True False

19. The mean of a normal probability distribution is 500 and the standard deviation is 10. About 95 percent of the observations lie between what two values? (Hint: Use the Empirical Rule) A. 475 and 525 B. 480 and 520 C. 400 and 600 D. 350 and 650

20. For the normal distribution, the mean plus and minus 1.96 standard deviations will include about what percent of the observations? A. 50% B. 99.7% C. 95% D. 68%

21. The weight of cans of fruit is normally distributed with a mean of 1,000 grams and a standard deviation of 50 grams. What percent of the cans weigh 860 grams or less? A. 0.0100 B. 0.8400 C. 0.0026 D. 0.0001

22. Truck tire life is normally distributed with a mean of 60,000 miles and a standard deviation of 4,000 miles. What is the probability that a tire lasts between 54,000 and 66,000 miles? A. 0.4332 B. 0.8664 C. 1.00 D. Very likely

23. Truck tire life is normally distributed with a mean of 60,000 miles and a standard deviation of 4,000 miles. You bought four tires. What is the probability that the average mileage of the four tires exceeds 66,000 miles? A. 0.0013 B. 0.9987 C. 0.4987 D. 0.9544

24. Construct the confidence interval estimate of the population proportion if the sample length the sample proportion 99% level of confidence. A. (0.176, 0.224) B. (0.171, 0.229) C. (0.162, 0.238) D. (0.157, 0.243)

25. A sample of 35 skulls is obtained for Egyptian males who lived around 1850 B.C. The maximum breadth of each skulls is measured with the result that the mean value of the sample mm and the standard deviation of the sample mm. Using these sample results and a confidence level of 95% find the confidence interval for the mean value of the maximum breadth of ancient Egyptian males. A. (133.3, 135.7) B. (132.9, 136.1) C. (133.0, 136.0) D. (132.6, 136.4)