Chapter 001 - Overview of Statistics 1-1 BADM 724 – Quant. Methods & Bus. Analytics Dr. Frank Tian Xie Class Assignment and Exercise Questions - Lecture 5 Our Team (circle one): A B C D Team Members...

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Chapter 001 - Overview of Statistics 1-1 BADM 724 – Quant. Methods & Bus. Analytics Dr. Frank Tian Xie Class Assignment and Exercise Questions - Lecture 5 Our Team (circle one): A B C D Team Members Present (first name): =============================================================== 1. If two events are complementary then we know that A. the sum of their probabilities is one. B. the joint probability of the two events is one. C. their intersection has a nonzero probability. D. they are independent events. 2. Find the probability that either event A or B occurs if the chance of A occurring is .5, the chances of B occurring is .3, and events A and B are independent. A. .80 B. .15 C. .65 D. .85 3. Given the contingency table shown here, find P(V). A. .20 B. .40 C. .50 D. .80 4. The following relationship always holds true for events A and B in a sample space. A. P(A | B) = P(B | A) B. P(A B) = P(A | B) P(B) C. P(A | B) = P(B | A) P(A) 1-2 5. Given the contingency table shown here, find P(A M). A. .2500 B. .7500 C. .6250 D. .1250 6. How many ways can we choose 3 items at random without replacement from 5 items (A, B, C, D, E) if the order of the selected items is not important? A. 60 B. 120 C. 10 D. 24 7. The value of 4P2 is A. 8 B. 6 C. 24 D. 12 8. Given the contingency table shown here, find P(A2). A. .1842 B. .1766 C. .8163 D. .0578 1-3 9. Given the contingency table shown here, find P(A3 B2). A. .3212 B. .2933 C. .0942 D. .1006 10. Given the contingency table shown here, does the decision to retire appear independent of the employee type? Survey question: Do you plan on retiring or keep working when you turn 65? A. Yes. B. No. Chapter 001 - Overview of Statistics 1-1 BADM 724 – Quant. Methods & Bus. Analytics Dr. Frank Tian Xie Class Assignment and Exercise Questions - Lecture 6 Our Team (circle one): A B C D Team Members Present (first name): =========================================================== 1. The discrete random variable X is the number of passengers waiting at a bus stop. The table below shows the probability distribution for X. What is the expected value E(X) for this distribution? A. 1.1 B. 1.3 C. 1.7 D. 1.9 2. The binomial distribution describes the number of A. trials to obtain the first "success" in a Bernoulli Process. B. trials to obtain n "successes" in a Bernoulli Process. C. "successes" or "failures" in a Bernoulli Process. D. "successes" in n Bernoulli trials. 3. A random variable X is distributed binomially with n = 8 and = 0.70. The standard deviation of the variable X is approximately A. 0.458 B. 2.828 C. 1.680 D. 1.296 4. On average, an IRS auditor discovers 4.7 fraudulent income tax returns per day. On a randomly chosen day, what is the probability that she discovers fewer than two? A. .0518 B. .0427 C. .1005 D. .1523 1-2 5. Which is a not a discrete random variable? A. The number of births in a hospital on a given day. B. The number of fives obtained in four rolls of a die. C. The hourly earnings of a call center employee in Boston. D. The number of applicants applying for a civil service job. 6. Which distribution is most nearly appropriate to describe the number of fatalities in Wisconsin per year due to poisonous snakebites? A. Binomial B. Poisson C. Uniform 7. A charity raffle prize is $1,000. The charity sells 4,000 raffle tickets. One winner will be selected at random. At what ticket price would a ticket buyer expect to break even? A. $0.50 B. $0.25 C. $ 0.75 D. $1.00 8. The gender of an unborn child is A. a continuous random variable. B. a discrete random variable. C. either a discrete or continuous random variable. 9. Which is not a discrete random variable? A. The number of defects in a 48 sheet of plywood. B. The number of female passengers who board a plane. C. The time until failure of a vehicle headlamp. D. The number of correct answers on a statistics exam. 10. Which probability model is most nearly correct to describe the number of burned-out fluorescent tubes in a classroom with 12 fluorescent tubes? A. Binomial B. Poisson C. Uniform 11. Which distribution has a mean of 5? A. Poisson with = 25. B. Binomial with n = 200, = .05 C. Uniform with a = 2, b = 8 1-3 12. A die is rolled. If it rolls to a 1, 2 or 3 you win $2. If it rolls to a 4, 5, 6 you lose $1. Find the expected winnings. A. $0.50 B. $3.00 C. $1.50 D. $1.00 13. A random variable X is distributed binomially with n = 8 and = 0.70. The standard deviation of the variable X is approximately A. 0.458 B. 2.828 C. 1.680 D. 1.296 14. On average, a major earthquake (Richter scale 6.0 or above) occurs 3 times a decade in a certain California county. Find the probability that at least one major earthquake will occur within the next decade. A. .7408 B. .1992 C. .1494 D. .9502