WGU C784 Statistics Module 7 (Latest ) Actual Exam Questions and Correct Answers

1. PROBABILITY Answer: it is the chance of an event occurring 2. PERCENTAGE Answer: parts of a whole 3. Impossible Answer: 0% possibility Probability that the day of the month will be 32 4. Unlikely Answer: 1% to 30% probability A snowstorm in Boston leaves more than 15 inches of snow 5. As likely as unlikely Answer: 40% to 60% probability A pregnant woman having a boy rather than a girl 6. Likely Answer: 70% to 99% probability The probability that a child born in the United States will live to adulthood 7. Certain Answer: 100% probability The probability that everyone alive today has a birthday 8. Decimal Expression of Percentage Answer: probability percentages range strictlyfrom 0% to 100% Therefore the decimal form of percentages range from 0 to 1 (remember to obtain the decimal form of a percentage, you divide by 100) 9. EXPERIMENT Answer: is the procedure, or situation, for which the probability is being calculated. So the roll of a die can be an experiment, a coin flip can be an experiment, or even the weather on a particular Wednesday 10. OUTCOME Answer: The possibilities of what can occur during an experiment—theresults of the experiment— When rolling a die, 1, 2, 3, 4, 5, and 6 are the possible outcomes 11. EVENT Answer: is comprised of one or more outcomes. The die landing on an even number is an event. The die landing on 1 is also anevent 12. FAIR Answer: if each outcome is equally likely. 13. P(E) Answer: The probability of an event is represented by P(E) which means probability (P) of a certain event (E) occurring. If R = Rain and the weatherman says there is a 40 percent chance of rain, then P(R) = 0.40. (Notice that the probability is written in its decimal form). 14. . An experiment is the procedure to test the occurrence of an event.Trueor False? Answer: FALSE An experiment is the procedure for which the probability of an event is calculated. 15. The possible results of an experiment are outcomes.True or False? Answer: - TRUE Each of the possible results from an experiment is known as an outcome. 16. The probability of an event occurring can be greater than 100%.True or False? Answer: false The probability of an event is always between 0% and 100%. 17. How can probability be expressed in numeric terms? Answer: FRACTIONS DECIMALS PERCENTS 18. What is an example of a fair experiment? Answer: flipping a coin This experiment has an equal probability for each possible outcome. 19. SET Answer: a collection of unique elements For example, a set of tree species is: oak, juniper, elm, maple. 20. SUBSET Answer: Set A is a subset* of set B, if every element in A is contained withinB. For example: A = {1, 2, 3} B = {1, 2, 3, 4, 5} A is a subset of B, because every element in set A is contained within set B. 21. EMPTY SET Answer: is a set that has no elements 22. UNION Answer: The union* of two sets is a collection of all of the elements listed in the sets For example: C = {2, 4, 6} D = {1, 3, 5} The union of C and D is {1, 2, 3, 4, 5, 6}, as those are all of the elements that appearin the sets. 23. INTERSECTION Answer: The intersection* of two sets is a collection of the elementslisted in both of the sets. E = {0, 10, 100} F = {-2, -1, 0, 1, 2} The intersection of E and F is {0}, as 0 is the only element that appears in both sets. 24. THEORETICAL (CLASSICAL) PROBABILITY Answer: based on what MAY happenor on a theory is calculated as the number of ways one particular event can occur in a random experiment, divided by the total number of possible outcomes: EACH OUTCOME MUST BE EQUALLY LIKELY 25. EMPIRICAL (OBSERVATIONAL) PROBABILITY Answer: Based on what ACTUALLYHAPPENS --estimated by relative frequency Relative frequency= # of times the event occured/Total # of trials 26. RELATIVE FREQUENCY Answer: i.e how often the event occurs in the series of trials(or experiments) relative to the number of trials. Relative frequency= # of times the event occured/Total # of trials 27. THE LAW OF LARGE NUMBERS Answer: as an experiment is repeated again and again, the empiracal probability will get closer and closer to the theoretical probability 28. RANDOM EXPERIMENTS Answer: are trials in which the outcome is not known aheadof time and the result does not depend on the results of other trials. 29. Joannie chooses a dessert recipe to bake for her book club meeting fromthe 25 dessert recipes she has in her recipe box.To predict the likelihood ofher making a chocolate chip cookie recipe next book club meeting, would the theoretical probability 1/25 be most accurate? Answer: NO She likely prefers some recipes over others or more often has the ingredients at hand. To help predict the future, an empirical probability will work best. 30. A die is rolled 10,000 times. We would most likely expect the relative frequency of rolling a "1" to converge on the value 1/6 True or False? Answer: TRUE 10,000 tosses is a large number. By the law of large numbers we would expect the relative frequency to be close to 1/6, the theoretical probability. 31. After a certain number of trials the empirical probability of an outcomewill equal the theoretical probability.True or False? Answer: FALSE The empirical probability will always be an estimate. 32. A researcher is testing the hypothesis that more screen time decreasesa person's ability to read social clues. The researcher is using surveys to gather information both about a person's screen time and about his or her ability to read social clues in order to be able to predict how well a person with a certain amount of screen time will be able to read social clues. How many surveys should the researcher collect? Answer: As many as possible.The law oflarge numbers holds that the more trials, the closer the empirical data comes to estimating the true probability. There is no way to calculate the theoretical probability in a case like this. The more data the researcher gathers the clearer an idea he or she will have about the extentof its influence (if any.) 33. Kiki the dog has a yellow, blue, green, and orange shirt. If her owner reaches into the drawer and picks one out at random, what is the probabilitythe shirt is NOT orange? Answer: ¾ 34. When rolling a fair, six-sided die, what is the probability of rolling a 2? Answer: 1/6 There is one outcome that corresponds with the desired event, out of six total possible outcomes 35. If you have a full, standard deck of cards, what is the probability of selecting a queen of hearts? Answer: 1/52 36. You have a jar of 7 marbles: 1 red marble, 2 green marbles, and 4 blue marbles. Selecting a marble at random, what is the probability that you selecta green marble? Answer: 2/7 37. You examine the number of times a player hit a home run this season, divided by the number of at-bats the player had.What is this an example of? Theoretical probability?Empirical Probability? The law of large Numbers? Answer: Empirical Probability We are using the number of times an event occurred to estimate the probability, therefore this is an example of empirical probability. 38. The Cardinals have won 100 of their 162 games. Using only this data, whatis the probability that the Cardinals win a game? Answer: 100/162 50/81 62% 39. When rolling a fair, six-sided die, what is the probability of rolling a 2 ora 3? Answer: 1/3 There are two outcomes that correspond with the desired event (rolling a two or a three), out of six total number of outcomes that can occur. 2/6 This fraction simplifies TO 1/3 40. You examine a deck of cards to determine the probability of selecting a certain group of cards. What is this an example of? Theoretical probability?Empirical Probability? The law of large Numbers? Answer: Theoretical probability We are using the number of times an outcome would occur, and they are all equally likely, this is an example of theoretical probability. 41. SAMPLE SPACE Answer: The set of possible outcomes in an experiment The sample space of rolling a regular six-sided die is 1, 2, 3, 4, 5, and 6 42. SAMPLE SIZE Answer: is the number of different outcomes the sample size of rolling a six-sided die is 6. 43. It is important to remember that the probabilities of all the outcomes in the sample space always sum to 1. Answer: That is, there is a 100 percent chance of one of the outcomes in the sample space happening, since the sample space, bydefinition, contains all possible outcomes. 44. What is the sample space for flipping 3 coins? Answer: The answer is 8. From the list constructed below, there are 8 outcomes.Heads, Heads, Heads Heads, Heads, TailsHeads, Tails, HeadsHeads, Tails, Tails Tails, Tails, Tails Tails, Tails, Heads Tails, Heads, Tails Tails, Heads, Heads 45. What is the sample space for rolling 1 dice and flipping 1 coin? Answer: Theanswer is 12. From the list that was constructed, there are 12 outcomes. 1, Heads 1, Tails 2, Heads 2, Tails 3, Heads 3, Tails 4, Heads 4, Tails 5, Heads 5, Tails 6, Heads 6, Tails 46. 3. What is the sample space for the order in which marbles are drawn outof a bag that contains 1 red, 1 yellow, and 1 green marble? Answer: The answer is 6.From the list that was constructed, there are 6 outcomes. Red, Yellow, Green Red, Green, Yellow Yellow, Red, GreenYellow, Green, Red Green, Red, YellowGreen, Yellow, Red 47. 4. What is the sample space for choosing an ice cream flavor (chocolate, strawberry, vanilla) and sauce (chocolate, caramel, or none)? Answer: The answer is 9. From the list that was constructed, there are 9 outcomes. Vanilla, Chocolate Vanilla, Caramel Vanilla, None Chocolate, ChocolateChocolate, Caramel Chocolate, None Strawberry, ChocolateStrawberry, Caramel Strawberry, None 48. Any experiment or trial will have only one sample space.True or False?- Answer: TRUE A sample space is the set of outcomes for one particular experiment, so any experiment has one unique sample space. 49. All events in the sample space have the same relative frequency.True or False? Answer: FALSE The relative frequency of an event is how often it happens in practice. We do not know if people who do not have inherited risk factors for heart disease decrease their risk of developing heart-related diseases by eating healthy until we gather data. It is reasonable to assume, however, that the relative frequency of different eating habits (healthy versus not-healthy) might not be equal. 50. In a tree diagram showing the sample space of an experiment, each new option increases the sample size.True or False? Answer: TRUE Each new option will be added to each of the previous options, increasing the size of the sample space dramatically. 51. A list, table, or tree diagram will show the exact same sample space.Trueor False? Answer: TRUE No matter the method used, each technique will have the same sample size. 52. The sample space and sample size represent the same thing.True or False? Answer: FALSE The sample space is a set of outcomes while the sample size is the number of different outcomes. 53. 1. The sample space can have equally likely outcomes.True or False? Answer: - TRUE Each outcome in a sample space can have the same chance of occurring. 54. 2. The probability using sample spaces with equally likely outcomes isthe number of outcomes in the event divided by the sample size. True or false? Answer: TRUE The probability is the number of outcomes in the event divided by the sample size. 55. 3. Using a tree diagram can result in probability greater than 1.True or False? Answer: FALSE The probability of an event can never be greater than 1. 56. 4. A tree diagram is the only method to determine the probability of an event.True or False? Answer: FALSE A list, table, tree diagram, and other methods can help determine the probability of an event. 57. 5. Finding the probability of events, given all outcomes are equally likely,has limited applications.True or False? Answer: TRUE Most probabilities are calculated when there are not equally likely outcomes. 58. Won Lost Won W,W W, L Lost L, W L, L What is the probability that you won both rounds of rocks-paper-scis-sors- shoot? Answer: 1/4 There are four equally likely outcomes. One of those outcomes involves winningboth rounds 59. Won Lost Won W,W W, LLost L, W L, L What is the probability that you lost both rounds of rocks-paper-scis-sors- shoot? Answer: 1/4 There are four equally likely outcomes.One of those outcomes involves losing both rounds 60. Won Lost Won W,W W, LLost L, W L, L What is the probability that you each win one round of rocks-paper-scis-sors-shoot, necessitating a third round? Answer: 1/2 here are four equally likely outcomes. Two of those outcomes involves you each winning one round of rocks-paper-scissors-shoot