Q&A Hero

Q: If A and B are independent events with P(A) = 0.4 and P(B) = 0.25, then P(A B) =a. 0.65b. 0.55c. 0.10d. Not enough information is given to answer this question.

Q: If A and B are independent events with P(A) = 0.2 and P(B) = 0.6, then P(A B) =a. 0.62b. 0.12c. 0.60d. 0.68

Q: If A and B are independent events with P(A) = 0.4 and P(B) = 0.6, then P(A B) =a. 0.76b. 1.00c. 0.24d. 0.2

Q: If P(A) = 0.5 and P(B) = 0.5, then P(A B) isa. 0.00b. 0.25c. 1.00d. cannot be determined from the information given

Q: On a December day, the probability of snow is .30. The probability of a "cold" day is .50. The probability of snow and a "cold" day is .15. Are snow and "cold" weather independent events? a. only if given that it snowed b. no c. yes d. only when they are also mutually exclusive

Q: If P(A) = 0.50, P(B) = 0.60, and P(A B) = 0.30; then events A and B are a. mutually exclusive events b. not independent events c. independent events d. Not enough information is given to answer this question.

Q: Two events with nonzero probabilities a. can be both mutually exclusive and independent b. cannot be both mutually exclusive and independent c. are always mutually exclusive d. cannot be both mutually exclusive and independent and are always mutually exclusive

Q: If X and Y are mutually exclusive events with P(X) = 0.295, P(Y) = 0.32, then P(XY) = a. 0.0944 b. 0.6150 c. 1.0000 d. 0.0000

Q: If A and B are independent events with P(A) = 0.38 and P(B) = 0.55, then P(AB) = a. 0.209 b. 0.000 c. 0.550 d. None of the other answers is correct.

Q: If two events are independent, then a. they must be mutually exclusive b. the sum of their probabilities must be equal to one c. the probability of their intersection must be zero d. None of the other answers is correct.

Q: If P(A) = 0.80, P(B) = 0.65, and P(A B) = 0.78, then P(BA) = a. 0.6700 b. 0.8375 c. 0.9750 d. Not enough information is given to answer this question.

Q: The multiplication law is potentially helpful when we are interested in computing the probability of a. mutually exclusive events b. the intersection of two events c. the union of two events d. None of the other answers is correct.

Q: Events A and B are mutually exclusive with P(A) = 0.3 and P(B) = 0.2. The probability of the complement of Event B equals a. 0.00 b. 0.06 c. 0.7 d. None of the other answers is correct.

Q: One of the basic requirements of probability is

Q: Which of the following statements is(are) always true?

Q: In an experiment, events A and B are mutually exclusive. If P(A) = 0.6, then the probability of B a. cannot be larger than 0.4 b. can be any value greater than 0.6 c. can be any value between 0 to 1 d. cannot be determined with the information given

Q: If A and B are mutually exclusive events with P(A) = 0.3 and P(B) = 0.5, thenP(A B) =a. 0.00b. 0.15c. 0.8d. 0.2

Q: If A and B are mutually exclusive events with P(A) = 0.3 and P(B) = 0.5, thenP(A B) =a. 0.30b. 0.15c. 0.00d. 0.20

Q: Two events, A and B, are mutually exclusive and each has a nonzero probability. If event A is known to occur, the probability of the occurrence of event B is a. one b. any positive value c. zero d. any value between 0 to 1

Q: If two events are mutually exclusive, then the probability of their intersection a. will be equal to zero b. can have any value larger than zero c. must be larger than zero, but less than one d. will be one

Q: The probability of the intersection of two mutually exclusive events a. can be any value between 0 to 1 b. must always be equal to 1 c. must always be equal to 0 d. can be any positive value

Q: Events that have no sample points in common are a. independent events b. posterior events c. mutually exclusive events d. complements

Q: Two events are mutually exclusive if a. the probability of their intersection is 1 b. they have no sample points in common c. the probability of their intersection is 0.5 d. the probability of their intersection is 1 and they have no sample points in common

Q: If P(A) = 0.85, P(A B) = 0.72, and P(A B) = 0.66, then P(B) =a. 0.15b. 0.53c. 0.28d. 0.15

Q: If P(A) = 0.62, P(B) = 0.47, and P(A B) = 0.88; then P(A B) =a. 0.2914b. 1.9700c. 0.6700d. 0.2100

Q: If P(A) = 0.38, P(B) = 0.83, and P(A B) = 0.57; then P(A B) =a. 1.21b. 0.64c. 0.78d. 1.78

Q: The addition law is potentially helpful when we are interested in computing the probability of a. independent events b. the intersection of two events c. the union of two events d. conditional events

Q: The symbol shows thea. union of eventsb. intersection of eventsc. sum of the probabilities of eventsd. None of the other answers is correct.

Q: The probability of the union of two events with nonzero probabilities a. cannot be less than one b. cannot be one c. cannot be less than one and cannot be one d. None of the other answers is correct.

Q: The union of events A and B is the event containing a. all the sample points common to both A and B b. all the sample points belonging to A or B c. all the sample points belonging to A or B or both d. all the sample points belonging to A or B, but not both

Q: The symbol shows thea. union of eventsb. intersection of eventsc. sum of the probabilities of eventsd. sample space

Q: Given that event E has a probability of 0.25, the probability of the complement of event E a. cannot be determined with the above information b. can have any value between zero and one c. must be 0.75 d. is 0.25

Q: A(n) __________ is a collection of sample points.a. probabilityb. permutationc. experimentd. event

Q: A(n) __________ is agraphical representation in which the sample space is represented by a rectangle and events are represented as circles. a. frequency polygon b. histogram c. Venn diagram d. tree diagram

Q: A graphical method of representing the sample points of a multiple-step experiment is a. a frequency polygon b. a histogram c. an ogive d. a tree diagram

Q: An experiment consists of four outcomes with P(E1) = 0.2, P(E2) = 0.3, and P(E3) = 0.4. The probability of outcome E4is a. 0.500 b. 0.024 c. 0.100 d. 0.900

Q: The probability assigned to each experimental outcome must be a. any value larger than zero b. smaller than zero c. one d. between zero and one

Q: Of the last 100 customers entering a computer shop, 25 have purchased a computer. If the classical method for computing probability is used, the probability that the next customer will purchase a computer is a. 0.25 b. 0.50 c. 1.00 d. 0.75

Q: A method of assigning probabilities based upon judgment is referred to as the a. relative method b. probability method c. classical method d. None of the other answers is correct.

Q: When the results of experimentation or historical data are used to assign probability values, the method used to assign probabilities is referred to as the a. relative frequency method b. subjective method c. classical method d. posterior method

Q: A method of assigning probabilities that assumes the experimental outcomes are equally likely is referred to as the a. objective method b. classical method c. subjective method d. experimental method

Q: When the assumption of equally likely outcomes is used to assign probability values, the method used to assign probabilities is referred to as the a. relative frequency method b. subjective method c. probability method d. classical method

Q: The "Top Three" at a racetrack consists of picking the correct order of the first three horses in a race. If there are 10 horses in a particular race, how many "Top Three" outcomes are there? a. 302,400 b. 720 c. 1,814,400 d. 10

Q: Of five letters (A, B, C, D, and E), two letters are to be selected at random. How many possible selections are there? a. 20 b. 7 c. 5! d. 10

Q: A graphical device used for enumerating sample points in a multiple-step experiment is a a. bar chart b. pie chart c. histogram d. None of the other answers is correct.

Q: Each customer entering a department store will either buy or not buy some merchandise. An experiment consists of following 3 customers and determining whether or not they purchase any merchandise. The number of sample points in this experiment is a. 2 b. 4 c. 6 d. 8

Q: Assume your favorite football team has 2 games left to finish the season. The outcome of each game can be win, lose or tie. The number of possible outcomes is a. 2 b. 4 c. 6 d. None of the other answers is correct.

Q: Three applications for admission to a local university are checked to determine whether each applicant is male or female. The number of sample points in this experiment is a. 2 b. 4 c. 6 d. 8

Q: A lottery is conducted using three urns. Each urn contains chips numbered from 0 to 9. One chip is selected at random from each urn. The total number of sample points in the sample space is a. 30 b. 100 c. 729 d. 1,000

Q: An experiment consists of tossing 4 coins successively. The number of sample points in this experiment is a. 16 b. 8 c. 4 d. 2

Q: An experiment consists of three steps. There are four possible results on the first step, three possible results on the second step, and two possible results on the third step. The total number of experimental outcomes is a. 9 b. 14 c. 24 d. 36

Q: The sample space refers to a. any particular experimental outcome b. the sample size minus one c. the set of all possible experimental outcomes d. both any particular experimental outcome and the set of all possible experimental outcomes are correct

Q: The set of all possible sample points (experimental outcomes) is called a. a sample b. an event c. the sample space d. a population

Q: The collection of all possible sample points in an experiment is a. the sample space b. a sample point c. an experiment d. the population

Q: A sample point refers to a(n) a. numerical measure of the likelihood of the occurrence of an event b. set of all possible experimental outcomes c. individual outcome of an experiment d. All of these answers are correct.

Q: Each individual outcome of an experiment is called a. the sample space b. a sample point c. an experiment d. an individual

Q: In statistical experiments, each time the experiment is repeated a. the same outcome must occur b. the same outcome can not occur again c. a different outcome may occur d. None of the other answers is correct.

Q: Any process that generates well-defined outcomes is a. an event b. an experiment c. a sample point d. None of the other answers is correct.

Q: Since the sun mustrise tomorrow, then the probability of the sun rising tomorrow is a. much larger than one b. zero c. infinity d. None of the other answers is correct.

Q: The range of probability is a. any value larger than zero b. any value between minus infinity to plus infinity c. zero to one d. any value between -1 to 1

Q: Posterior probabilities are a. simple probabilities b. marginal probabilities c. joint probabilities d. conditional probabilities

Q: If Aand Bare mutually exclusive, thena. P(A) + P(B) = 0b. P(A) + P(B) = 1c. P(A B) = 0d. P(A B) = 1

Q: The probability of an intersection of two events is computed using the a. addition law b. subtraction law c. multiplication law d. division law

Q: An element of the sample space is a. an event b. an estimator c. a sample point d. an outlier

Q: The complement of P(A| B) is a. P(AC| B) b. P(A| BC) c. P(B| A) d. P(AB)

Q: Posterior probabilities are computed using a. the classical method b. Chebyshev's theorem c. the empirical rule d. Bayes' theorem

Q: Revised probabilities of events based on additional information are a. joint probabilities b. posterior probabilities c. marginal probabilities d. complementary probabilities

Q: The probability of at least one head in two flips of a coin is a. 0.33 b. 0.50 c. 0.75 d. 1.00

Q: Which of the following symbols represents the size of the population?a. s 2b. sc. md. N

Q: The descriptive measure that is not measured in the same units as the original data is the a. median b. standard deviation c. mode d. variance

Q: If two groups of numbers have the same mean, then their a. standard deviations must also be equal b. medians must also be equal c. modes must also be equal d. None of the other answers are correct.

Q: The descriptive measure of dispersion that is based on the concept of a deviation about the mean is a. the range b. the interquartile range c. both the range and the interquartile range d. the standard deviation

Q: The measure of dispersion that is influenced most by extreme values is a. the variance b. the standard deviation c. the range d. the interquartile range

Q: Which of the following is not a measure of dispersion? a. the range b. the 50th percentile c. the standard deviation d. the interquartile range

Q: Which of the following is a measure of dispersion? a. percentiles b. quartiles c. interquartile range d. all of these are measures of dispersion

Q: The weights (in pounds) of a sample of 36 individuals were recorded and the following statistics were calculatedmean = 160range = 60mode = 165variance = 324median = 170The coefficient of variation equalsa. 0.1125%b. 11.25%c. 203.12%d. 0.20312%

Q: The coefficient of variation is a. the same as the variance b. the square root of the variance c. the square of the standard deviation d. None of the other answers are correct.

Q: Excel's __________ function can be used to compute the population standard deviation. a. MAX b. MODE c. STDEV d. None of the other answers are correct.

Q: Excel's __________ function can be used to compute the sample standard deviation. a. MAX b. MODE c. VAR d. STDEV

Q: Excel's __________ function can be used to compute the population variance. a. MAX b. MODE c. VAR d. None of the other answers are correct.