ISM6137 Exam 2

Correlation is affected by the measurement scales applied to the X and Y variables.

False

If A and B are independent events with P(A) = 0.40 and P(B) = 0.50, then P(A/B) is 0.50.

False

If the standard deviation of X is 15, the covariance of X and Y is 94.5, and the correlation is 0.90, then the variance of Y is 7.0.

False

Linear programming problems can always be formulated algebraically, but not always on a spreadsheet.

False

The multiplication rule for two events A and B is: P(A and B) = P(A|B)P(A).

False

The relative frequency of an event is the number of times the event occurs out of the total number of times the random experiment is run.

False

If events A and B are mutually exclusive, then the probability of both events occurring simultaneously is equal to:

0.0

If two events are mutually exclusive, what is the probability that both occur at the same time?

0.00

Which of the following statements are false regarding the numbers generated by the RAND function in Excel®?

The numbers are probabilistically dependent.

If P(A) = 0.25 and P(B) = 0.65, then P(A and B) is:

This cannot be determined from the information given.

A discrete distribution is useful for many situations, either when the uncertain quantity is not continuous (the number of televisions demanded, for example) or when we want a discrete approximation to a continuous variable.

True

A frequency table indicates how many observations fall within each category, and a histogram is its graphical analog.

True

A probability distribution is continuous if its possible values fall alongy some continuum.

True

A shadow price indicates how much a company would pay for more of a scarce resource.​

True

Age, height, and weight are examples of numerical data.

True

Spreadsheet simulation modeling is quite similar to the other modeling applications in that it begins with input variables and then relates these with appropriate Excel® formulas to produce output variables of interest.

True

The correlation between two variables is unitless and always between -1 and +1.

True

The feasible region in a graphical solution of a linear programming problem will appear as some type of polygon, with lines forming all sides.

True

The number of car insurance policy holders is an example of a discrete numerical variable.

True

The triangular distribution is sometimes used in simulation models because it is more flexible and intuitive than the normal distribution.

True

When determining the most appropriate input probability distribution in a simulation model, first select the most appropriate family, and then select the most appropriate member of that family.

True

When the proportionality property of LP models is violated, we generally must use non-linear optimization.

True

In general, important characteristics of probability distributions include the following distinctions:

all of these choices

Gender and states of residence are examples of ____ data.

categorical

Displaying all correlations between 0.6 and 0.999 on a scatterplot as green and all correlations between -1.0 and -0.6 as red is known as _____ formatting.

conditional

A sample of a population taken at one particular point in time is categorized as:

cross-sectional

If P(A) = P(A|B), then events A and B are said to be:

independent

The length of the box in the box plot portrays the:

interquartile range

As a measure of variability, what is defined as the maximum value minus the minimum value?

range

Which correlation coefficient suggests the strongest relationship?

+1

Relationships between two variables are less evident when counts are expressed as percentages of row totals or column totals.

False

The set of all values of the decision variable cells that satisfy all constraints, not including the nonnegativity constraints, is called the feasible region.

False

There is often more than one objective in linear programming problems.

False

An example of a joint category of two variables is the count of all non-drinkers who are also nonsmokers.

True

Both ordinal and nominal variables are categorical.

True

Football teams toss a coin to see who will get their choice of kicking or receiving to begin a game. The probability that given team will win the toss three games in a row is 0.125.

True

If P(A and B) = 1, then A and B must be collectively exhaustive.

True

It is often useful to perform sensitivity analysis to see how, or if, the optimal solution to a linear programming problem changes as we change one or more model inputs.

True

Scatterplots are also referred to as

X-Y charts.

Suppose a firm must at least meet minimum expected demands of 60 for product x and 80 of product y. An algebraic formulation of these constraints is:

X>=60, Y>=80

The deterministic (non-simulation) approach, using best guesses for the uncertain inputs, is:

generally not the appropriate model

The average score for a class of 30 students was 75. The 20 male students in the class averaged 70. The 10 female students in the class averaged:

higher than the males

A probability distribution is bounded if there are values A and B such that:

no value can be less than A or greater than B

In most cases, when solving linear programming problems, we want the decision variables to be:

nonnegative

When n is reasonably large and p isn't too close to 0 or 1, the binomial distribution can be well approximated by which of the following distributions?

normal distribution

In an optimization model, there can only be one:

objective function

The law of large numbers is relevant to the estimation of:

objective probabilities

How is the median defined if the number of observations is even?

the average of the two middle observations