BUS172 Exam Chap 1-3
When the conclusions based upon the aggregated crosstabulation can be completely reversed if we look at the unaggregated data, the occurrence is known as
Simpson's paradox
If one wanted to find the probability of ten customer arrivals in an hour at a service station, one would generally use the
Poisson probability distribution
If A and B are mutually exclusive events with P(A) = 0.3 and P(B) = 0.5, then P(A ∩ B) =
0.00 (exclusive event = 0)
A probability distribution showing the probability of x successes in n trials, where the probability of success does not change from trial to trial, is termed a
binomial probability distribution
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
binomial probability function
The volume that results in total revenue being equal to total cost is the
break-even point.
The quantitative analysis approach requires
mathematical expressions for the relationships.
A model that uses a system of symbols to represent a problem is called
mathematical.
The probability of an intersection of two events is computed using the
multiplication law
A binomial probability distribution with p = .3 is
negatively skewed
The binomial probability distribution is most symmetric when
p equals 0.5
Revised probabilities of events based on additional information are
posterior probabilities
Management science and operations research both involve
quantitative approaches to decision making.
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
relative frequency method
Decision alternatives
should be identified before decision criteria are established.
In order to measure the dispersion of a random variable, look at its
standard deviation.
A list of all possible outcomes of an experiment is called
the sample space.
George Dantzig is important in the history of management science because he developed
the simplex method for linear programming.
Whenever the probability is proportional to the length of the interval, the random variable is
uniformly distributed
Larger values of the standard deviation result in a normal curve that is
wider and flatter
The range of probability is
zero to one
In a Poisson probability problem, the rate of errors is one every two hours. To find the probability of three defects in four hours,
λ = 2, x = 3
Z is a standard normal random variable. The P(1.05 < z < 2.13) equals
0.1303
The scientific management revolution of the early 1900s was initiated by
Frederic Taylor
When production volume exceeds the breakeven point, we can expected
a profit
A physical model that does not have the same physical appearance as the object being modeled is
an iconic model
Which of the following is not one of the commonly used names for the body of knowledge involving quantitative approaches to decision-making?
efficiency studies
The uniform distribution defined over the interval from 25 to 40 has the probability density function
f(x) = 1/15 for 25 ≤ x ≤ 40 and f(x) = 0 elsewhere
One of the basic requirements of probability is
if there are k experimental outcomes, then P(E1) + P(E2) + ... + P(Ek) = 1
Before drawing any conclusions about the relationship between two variables shown in a crosstabulation, you should
investigate whether any hidden variables could affect the conclusions
Identification and definition of a problem
is the first step of decision making.
Problem definition
-must occur prior to the quantitative analysis process. -involve the analyst and the user of the results. -includes specific objectives and operating constraints.
The expected value for a binomial probability distribution is
E(x) = np
An experiment consists of four outcomes with P(E1) = 0.2, P(E2) = 0.3, and P(E3) = 0.4. The probability of outcome E4 is
0.100
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
0.50
If P(A) = 0.38, P(B) = 0.83, and P(A B) = 0.27; then P(A B) =
0.94
For a standard normal distribution, the probability of obtaining a z value of less than 1.6 is
0.9452
The probability of at least one head in two flips of a coin is
1.00
When the exponential distribution probability is given as P(x ≤ 9 ) = 1 − e−9/18 the average value for x is
18
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
8
Posterior probabilities are computed using
Bayes' theorem
If P(A|B) = .4, then
None of the alternatives is correct.
A graphical device used for enumerating sample points in a multiple-step experiment is a
None of the other answers is correct.
The complement of P(A | B) is
P(A n B)
If x is normally distributed with mean 12 and standard deviation 2, then P(x ≤ 9) is
P(z ≤ −3/2)
When dealing with the number of occurrences of an event over a specified interval of time or space and when the occurrence or nonoccurrence in any interval is independent of the occurrence or nonoccurrence in any other interval, the appropriate probability distribution is a
Poisson distribution
The weight of an object, measured to the nearest gram, is an example of
a discrete random variable
A standard normal distribution is a normal distribution with
a mean of 0 and a standard deviation of 1
A numerical description of the outcome of an experiment is
a random variable.
An element of the sample space is
a sample point
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 complement of A is
all accounts fewer than 31 or more than 60 days past due.
The union of events A and B is the event containing
all the sample points belonging to A or B or both
A physical model that does not have the same physical appearance as the object being modeled is
an analog model.
Any process that generates well-defined outcomes is
an experiment
Decision criteria
are the ways to evaluate the choices faced by the decision maker.
Inputs to a quantitative model
are uncertain for a stochastic model.
A probability density function
describes the graph whose underlying area represents probability over an interval.
If P(A|B) = .2 and P(Bc) = .6, then P(B|A)
cannot be determined.
A method of assigning probabilities that assumes the experimental outcomes are equally likely is referred to as the
classical method
Experimental outcomes that are based on measurement scales such as time, weight, and distance can be described by _____ random variables.
continuous
An experiment consists of measuring the speed of automobiles on a highway by the use of radar equipment. The random variable in this experiment is speed, measured in miles per hour. This random variable is a
continuous random variable
The decision variables of a model are also known as the
controllable inputs
The field of management science
each of these choices are true.
Experiments with repeated independent trials will be described by the binomial distribution if
each trial has exactly two outcomes whose probabilities do not change.
When the value of the output cannot be determined even if the value of the controllable input is known, the model is
stochastic.
In a multicriteria decision problem
the decision maker must evaluate each alternative with respect to each criterion.
The first step in problem solving is
the identification of a difference between the actual and desired state of affairs.
