BADM 410    Practice Test 1   Spring 2004   Dr. Silver

Answer both of the problems below.  You may use notes, books, and calculators.

 

1.      Find the optimal strategies for the two players and the expected value of the following two-person, zero-sum game.

 

   A's Payoff Matrix

 

 

B1

B2

A1

8

-5

A2

-4

10

 

 

2.       Given the following returns for an investment project, in $ thousands, find the optimal investment level using four criteria:  maximax, minimax regret, maximin, and the maximum expected value; calculate the standard deviations for the three investment levels, as well. Also calculate the expected value of perfect information.

 

State of Nature

 

Investment Level

Good

So-so

Bad

Expected Value

High

400

250

-400

 

Medium

300

100

-100

 

Low (zero)

0

0

0

 

Probabilities

.2

.5

.3

 

 

3.      A mid-western city is trying to determine how large an arena to build for its new hockey team.  A consultant has estimated that demand for tickets, that is, seats, for each game at the expected price of $15 is normally-distributed with a mean of 12,000 and standard deviation of 5000.  According to the engineering contractor building the arena the cost per seat per game for the expected life of the arena is estimated at $5.  How many seats should the arena have?

 

 


Statistics Test.

 

4.         The data below are a random sample of mortgage rates, in percent, in the Washington, D.C. metropolitan area for the week of January 4-8, 2004.

 

            5.50     5.75     6.25     5.75     5.8

 

a.         Calculate the sample mean, mode, median, range and standard deviation for the data. 

b.         Another sample of 40 rates revealed a sample mean of 5.85 and a standard deviation of .32.  Construct a 90 percent confidence interval for mortgage rates in the area. 

c.         If the true mean mortgage rate and standard deviation are 5.8 and .30, respectively, what can be said about the proportion of mortgage rates in excess of 6.25 percent if

            i)   nothing is known about the distribution of mortgage rates?

            ii)  the distribution of mortgage rates is mound-shaped?

 

5.         The table below lists the probability distribution for the number of absences of Citadel cadets in my production ops class during a semester:

  

Absences (X)

P(X)

 

 

 

0

.2

 

 

 

1

.3

 

 

 

2

.3

 

 

 

3

.1

 

 

 

4

.1

 

 

 

 

a.         Find the expected number of classes missed by a student and the standard deviation.

b.         What is the probability that a student, chosen at random, will miss more than two classes?

c.         During a semester with 60 enrollments in two sections, what is the probability that the sample mean of the number of classes missed will exceed 2?  [Assume that my students this semester constitute a random sample]

 

6.    The probability that a part is defective is .01.

            a.         Find the probability of exactly one defect in twenty parts tested at random.

            b.         Find the probability of more than six defects in a random sample of 360 parts.

c.         What is the probability that between 15 and 25 defects in a random sample of 1850 parts tested?