QBA Exam 1

The objective function for a LP model is 3 X1 + 2 X2. If X1 = 20 and X2 = 30, what is the value of the objective function?

120

A diet is being developed which must contain at least 100 mg of vitamin C. Two fruits are used in this diet. Bananas contain 30 mg of vitamin C and Apples contain 20 mg of vitamin C. The diet must contain at least 100 mg of vitamin C. Which of the following constraints reflects the relationship between Bananas, Apples and vitamin C?

20 A + 30 B ≥ 100

A company uses 4 pounds of resource 1 to make each unit of X1 and 3 pounds of resource 1 to make each unit of X2. There are only 150 pounds of resource 1 available. Which of the following constraints reflects the relationship between X1, X2 and resource 1?

4 X1 + 3 X2 ≤ 150

The constraint for resource 1 is 5 X1 + 4 X2 ≤ 200. If X1 = 20 and X2 = 5, how much of resource 1 is unused?

80

Which command is equivalent to =SUMPRODUCT(A1:A3,B1:B3)?

=A1*B1+A2*B2+A3*B3

Which of the following describes an additive seasonal effect in times series data?

A regular, repeating pattern of equal magnitude

Which of the following is true of "What if?" analysis?

A well-designed spreadsheet facilitates "What if?" analysis.

Why might a forecaster calculate MSE values on just the most recent data in the time-series data set?

All of these.

The correct formula for a k period moving average is

B

Which of the following is not a quantitative technique for evaluating the accuracy of a time-series modeling technique?

Constructing line graphs of the data.

What is the goal in optimization?

Find the decision variable values that result in the best objective function and satisfy all constraints

A mathematical model is considered to be "valid" when?

It accurately represents the relevant characteristics of the object or decision.

Which of the following actions would expand the feasible region of an LP model?

Loosening the constraints

The determination of the MSE-minimizing value of the wi is a non-linear optimization problem because

MSE is a non-linear objective function

Which type of spreadsheet cell represents the objective function in an LP model?

Objective cell

In the following expression, which is (are) the dependent variable(s)? PROFIT = REVENUE − EXPENSES

Profit

Variables are termed independent when they satisfy which of the following?

The function value depends upon their values.

Which of the following is the common approach to time-series analysis?

Try several techniques and use the best results

A company makes two products, X1 and X2. They require at least 20 of each be produced. Which set of lower bound constraints reflect this requirement?

X1 ≥ 20, X2 ≥ 20

A heuristic solution is

a rule-of-thumb for making decisions.

The best models

accurately reflect relevant characteristics of the real-world object or decision.

A model or technique that uses past behavior of a time-series variable to predict the future is referred to as

all of these

The essence of decision analysis is:

choosing the best course of action among alternatives.

A manager has only 200 tons of plastic for his company. This is an example of a(n)

constraint.

The number of units to ship from Chicago to Memphis is an example of a(n)

decision

What are the three common elements of an optimization problem?

decisions, constraints, an objective

The constraints of an LP model define the

feasible region

Benefits of sensitivity analysis include all the following except:

fosters managerial acceptance of the optimal solution.

In a spreadsheet, input cells correspond conceptually to

independent variables.

A common objective in the product mix problem is

maximizing profit.

If the shadow price for a resource is 0 and 150 units of the resource are added what happens to the objective function value?

no increase

The constraints X1 ≥ 0 and X2 ≥ 0 are referred to as

nonnegativity conditions.

The desire to maximize profits is an example of a(n)

objective

Seasonality in a time series is indicated by

regular, repeating patterns in the data around a trend line.

A time series which has no significant upward or downward trend is referred to as

stationary

The allowable decrease for a constraint is

the amount by which the resource can decrease given shadow price.

The allowable increase for a constraint is

the amount by which the resource can increase given shadow price.

The reduced cost for a changing cell (decision variable) is

the per unit profits minus the per unit costs for that variable.

The shadow price of a nonbinding constraint is

zero

Binding constraints have

zero slack