University of the Incarnate WordPMBA 6312 Week 4 Mid-Term. PMBA 6312 Quantitative Methods / Research. Contains 40 Questions and Answers

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Week 4 – Mid-term Question 1 If A and B are mutually exclusive events with P(A) = 0.3 and P(B) = 0.5, then P(A ∩ B) = a. 0.20 b. 0.30 c. 0.15 d. 0.00 Question 2 Variance is a. a measure o... f the average, or central value of a random variable b. the square root of the standard deviation c. the sum of the deviation of data elements from the mean d. a measure of the dispersion of a random variable Question 3 If P(A B) = 0 a. either P(A) = 0 or P(B) = 0. b. A and B are mutually exclusive events. c. P(A) + P(B) = 1 d. A and B are independent events. Question 4 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. Question 5 The probability of at least one head in two flips of a coin is a.0.75 b.1.00 c. 0.50 d.0.33 175 out of 200 Question 6 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 Question 7 All of the following are true about a stationary time series except a.There is no variability in the time series over time. b.Its statistical properties are independent of time. c. A plot of the series will always exhibit a horizontal pattern. d.The process generating the data has a constant mean Question 8 A posterior probability associated with sample information is of the form a. P (a decision alternative | a sample outcome) b. P (a state of nature | a sample outcome) c. P (a sample outcome | a decision alternative) d. P (a sample outcome | a state of nature) Question 9 z is a standard normal random variable. The P( z ≥ 2.11) equals a. 0.4821 b.0.9821 c. 0.0174 d.0.5 Question 10 The trend pattern is easy to identify by using a. a weighted moving average b. a moving average c. exponential smoothing d. regression analysis Question 11 Events A and B are mutually exclusive. Which of the following statements is also true? a. P(A Υ B) = P(A)P(B) b. P(A Υ B) = P(A) + P(B) c. P(A ∩ B) = P(A) + P(B) d. A and B are also independent Question 12 A decision tree a.arranges decision alternatives and states of nature in their natural chronological order. b.presents all decision alternatives first and follows them with all states of nature. c. alternates the decision alternatives and states of nature. d.presents all states of nature first and follows them with all decision alternatives. Question 13 The binomial probability distribution is most symmetric when a. n is 30 or greater b.n equals p c. p equals 0.5 d.p approaches 1 Question 14 The approach to determining the optimal decision strategy involves a. a forward (left to right) pass through the decision tree. b. choosing the outcome of a chance event with the greatest payoff. c. a backward (right to left) pass through the decision tree. d. choosing the outcome of a chance event with the greatest probability. Question 15 For a maximization problem, the optimistic approach is often referred to as the a. maximax approach b. minimax approach c. maximin approach d. minimin approach Question 16 Posterior probabilities are a. joint probabilities b.simple probabilities c. conditional probabilities d.marginal probabilities Question 17 The difference between the expected value of an optimal strategy based on sample information and the "best" expected value without any sample information is called the a. efficiency of sample information. b. expected value of sample information. c. expected value of perfect information. d. information sensitivity. Question 18 If one wanted to find the probability of ten customer arrivals in an hour at a service station, one would generally use the a. binomial probability distribution b. Poisson probability distribution c. uniform probability distribution d. exponential probability distribution Question 19 Using exponential smoothing, the demand forecast for time period 10 equals the demand forecast for time period 9 plus a. α times (the demand forecast for time period 8) b. α times (the error in the demand forecast for time period 9) c. α times (the observed demand in time period 9) d. α times (the demand forecast for time period 9) Question 20 If one wanted to find the probability of ten customer arrivals in an hour at a service station, one would generally use the a. exponential probability distribution b. hypergeometric probability distribution c. binomial probability distribution d. Poisson probability distribution Question 21 Gradual shifting of a time series to relatively higher or lower values over a long period of time is called a. periodicity. b. trend. c. seasonality. d. cycles. Question 22 Whenever the probability is proportional to the length of the interval, the random variable is a. normally distributed b. exponentially distributed c. binomially distributed d. uniformly distributed Question 23 If you are conducting an experiment where the probability of a success is .02 and you are interested in the probability of 4 successes in 15 trials, the correct probability function to use is the a. standard normal probability density function b.normal probability density function c. binomial probability function d.Poisson probability function Question 24 Application of Bayes’ theorem enables us to compute a. the posterior probability of each sample outcome b. the prior probability of each state of nature c. the conditional probability of the sample outcomes given each state of nature d. the conditional probability of the states of nature given each sample outcome Question 25 The forecasting method that is appropriate when the time series has no significant trend, cyclical, or seasonal pattern is a. qualitative forecasting b.mean squared error c. moving average d.mean average error Question 26 If P(high) = .3, P(low) = .7, P(favorable | high) = .9, and P(unfavorable | low) = .6, then P(favorable) = a. .27 b. .10 c. .30 d. .55 Question 27 Making a good decision a. requires probabilities for all states of nature. b. requires a clear understanding of decision alternatives, states of nature, and payoffs. c. implies that a desirable outcome will occur. d. All of the alternatives are true. Question 28 Whenever a categorical variable such as season has k levels, the number of dummy variables required a. k b.2 k c. k - 1 d. k + 1 Question 29 Z is a standard normal random variable. The P(1.20 £ z £ 1.85) equals a. 0.3849 b. 0.0829 c. 0.4678 d. 0.8527 Question 30 The Poisson probability distribution is used with a. a continuous random variable b. either a discrete or continuous random variable c. any random variable d. a discrete random variable Question 31 To find the EVSI, a. use the EVPI to calculate sample information probabilities. b. use prior and sample information probabilities to calculate revised probabilities. c. use sample information to revise the sample information probabilities. d. use indicator probabilities to calculate prior probabilities. Question 32 When the exponential distribution probability is given as P( x ≤ 9 ) = 1 - e -9/18 the average value for x is a.18 b.1/2 c. 9 d.9/18 Question 33 In the set of all past due accounts, let the event A mean the account is between 31 and 60 days past due and the event B mean the account is that of a new customer. The union of A and B is a. all accounts from new customers and all accounts that are from 31 to 60 days past due. b. all accounts fewer than 31 or more than 60 days past due. c. all new customers whose accounts are between 31 and 60 days past due. d. all new customers. Question 34 Z is a standard normal random variable. The P(1.05 £ z £ 2.13) equals a. 0.6618 b.0.4834 c. 0.1303 d.0.8365 Question 35 A sequence of decisions and chance outcomes that provide the optimal solution to a decision problem is called a. the expected value approach b. a decision strategy c. a payoff table d. a contingency plan Question 36 Z is a standard normal random variable. What is the value of z if the area to the right of z is 0.9803? a.-2.06 b.0.4803 c. 0.0997 d.3.06 Question 37 One measure of the accuracy of a forecasting model is the a. smoothing constant b. linear trend c. seasonal index d. mean absolute error Question 38 If you are conducting an experiment where the probability of a success is .02 and you are interested in the probability of 4 successes in 15 trials, the correct probability function to use is the a. binomial probability function b. Poisson probability function c. normal probability density function d. standard normal probability density function Question 39 Posterior probabilities are computed using a.Bayes’ theorem b.the classical method c. Chebyshev’s theorem d.the empirical rule Question 40 Which of the following statements is(are) always true? a. P(A) + P(B) = 1 b. -1 ≤ P(E i) ≤ 1 c. P(A) = 1 - P(A c) d. both P(A) = 1 - P(A c) and P(A) + P(B) = 1 [Show More]

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