STATS Exam: 250712RR – Probability (2015)

When you have completed your exam and reviewed your answers, click Submit Exam. Answers will not be recorded until you hit Submit Exam. If you need to exit before completing the exam, click Cancel Exam.Questions 1 to 20: Select the best answer to each question. Note that a question and its answers may be split across a page break, so be sure that you have seen the entire question and all the answers before choosing an answer.1. In the binomial probability distribution, p stands for theA. probability of success in any given trial.B. probability of failure in any given trial.C. number of successes.D. number of trials.2. Which of the following is a discrete random variable?A. The weight of football players in the NFLB. The number of three-point shots completed in a college basketball gameC. The average daily consumption of water in a householdD. The time required to drive from Dallas to Denver3. The Burger Bin fast-food restaurant sells a mean of 24 burgers an hour and its burger sales are normally distributed. The standard deviation is 6. What is the probability that the Burger Bin will sell 12 to 18 burgers in an hour?A. 0.475B. 0.239C. 0.342D. 0.1364. What is the value of ?A. 336B. 1.6C. 6720D. 565. The Burger Bin fast-food restaurant sells a mean of 24 burgers an hour and its burger sales are normally distributed. If hourly sales fall between 24 and 42 burgers 49.85% of the time, the standard deviation is _______ burgers.A. 6B. 3C. 18D. 96. Assume that an event A contains 10 observations and event B contains 15 observations. If the intersection of events A and B contains exactly 3 observations, how many observations are in the union of these two events?A. 22B. 0C. 10D. 287. A breeder records probabilities for two variables in a population of animals using the two-way table given here. Let A be the event “shaggy and brown-haired.” Compute P(Ac). Brown-haired BlondShort-haired 0.06 0.23Shaggy 0.51 0.20A. 0.49B. 0.51C. 0.36D. 0.778. If event A and event B are mutually exclusive, P(A or B) =A. P(A + B).B. P(A) + P(B) – P(A and B).C. P(A) + P(B).D. P(A) – P(B).9. Consider an experiment that results in a positive outcome with probability 0.38 and a negative outcome with probability 0.62. Create a new experiment consisting of repeating the original experiment 3 times. Assume each repetition is independent of the others. What is the probability of three successes?A. 0.055B. 1.14C. 0.238D. 0.76210. A continuous probability distribution represents a random variableA. having an infinite number of outcomes that may assume any number of values within an interval.B. that’s best described in a histogram.C. that has a definite probability for the occurrence of a given integer.D. having outcomes that occur in counting numbers.11. Which of the following is correct concerning the Poisson distribution?A. The event being studied is restricted to a given span of time, space, or distance.B. The mean is usually larger than the variance.C. The mean is usually smaller than the variance.D. Each event being studied must be statistically dependent on the previous event. Protestant Catholic Jewish OtherDemocrat 0.35 0.10 0.03 0.02Republican 0.27 0.09 0.02 0.01Independent 0.05 0.03 0.02 0.01 12. The table above gives the probabilities of combinations of religion and political parties in a city in the United States. What is the probability that a randomly selected person will be a Protestant and at the same time be a Democrat or a Republican?A. 0.62B. 0.89C. 0.67D. 0.3513. A basketball team at a university is composed of ten players. The team is made up of players who play the position of either guard, forward, or center. Four of the ten are guards, four are forwards, and two are centers. The numbers that the players wear on their shirts are 1, 2, 3, and 4 for the guards; 5, 6, 7, and 8 for the forwards; and 9 and 10 for the centers. The starting five are numbered 1, 3, 5, 7, and 9. Let a player be selected at random from the ten. The events are defined as follows:Let A be the event that the player selected has a number from 1 to 8.Let B be the event that the player selected is a guard.Let C be the event that the player selected is a forward.Let D be the event that the player selected is a starter.Let E be the event that the player selected is a center. Calculate P(C).A. 0.50B. 0.80C. 0.40D. 0.2014. Each football game begins with a coin toss in the presence of the captains from the two opposing teams. (The winner of the toss has the choice of goals or of kicking or receiving the first kickoff.) A particular football team is scheduled to play 10 games this season. Let x = the number of coin tosses that the team captain wins during the season. Using the appropriate table in your textbook, solve for P(4 ? x ? 8).A. 0.246B. 0.817C. 0.171D. 0.37715. Approximately how much of the total area under the normal curve will be in the interval spanning 2 standard deviations on either side of the mean?A. 50%B. 68.3%C. 95.5%D. 99.7%16. If the probability that an event will happen is 0.3, what is the probability of the event’s complement?A. 0.1B. 0.7C. 1.0D. 0.317. The area under the normal curve extending to the right from the midpoint to z is 0.17. Using the standard normal table on the textbook’s back endsheet, identify the relevant z value.A. –0.0675B. 0.44C. 0.0675D. 0.455418. For each car entering the drive-through of a fast-food restaurant, x = the number of occupants. In this study, x is aA. dependent event.B. joint probability.C. continuous quantitative variable.D. discrete random variable.19. A breeder records probabilities for two variables in a population of animals using the two-way table given here. Given that an animal is brown-haired, what is the probability that it’s short-haired? Brown-haired BlondShort-haired 0.06 0.23Shaggy 0.51 0.20A. 0.0306B. 0.222C. 0.06D. 0.10520. Let event A = rolling a 1 on a die, and let event B = rolling an even number on a die. Which of the following is correct concerning these two events?A. Events A and B are exhaustive.B. On a Venn diagram, event A would overlap event B.C. Events A and B are mutually exclusive.D. On a Venn diagram, event B would contain event A.