Ashford University BUS 308 Week 1 Problems (statistics for managers)

Week 1 Business Statistics
Student Name
BUS308: Statistics for Managers (BAM1146A)
Instructor’s
Name
Date

Week 1 Business Statistics
1.2 Which of these variables are quantitative and
which are qualitative?
a. The
dollar amount on accounts receivable invoice.
b. The
net profit for a company in 2009.
c. The
stock exchange on which a company’s stock is traded.
d. The
national debt of the United States in 2009.
e. The
advertising medium (radio, television, or print) used to promote a product.

1.17 Classify each of the following
qualitative variables as ordinal or nominative.
Qualitative
Variable Categories
Statistics
course letter grade A B
C D F
Door
choice on Let’s Make A Deal Door
#1 Door #2
Television
show classifications TV-G TV-PG
TV-14 TV-MA
Personal
computer ownership Yes No
Restaurant
rating ***** ****
*** ** *
Income
tax filing status Married
filing jointly Married filing
separately
Single Head
of household Qualifying widow(er)
3.3 Calculate the mean, median, and mode of each
of the following populations of numbers:
a.
9, 8, 10, 10,
12, 6, 11, 10, 12, 8

b.
110,
120, 70, 90, 90, 100, 80, 130, 140

3.22 In order
to control costs, a company wishes to study the amount of money its sales force
spends entertaining clients. The
following is a random sample of six entertainment expenses (dinner cost for
four people) from expense report submitted by members of the sales force.
$157 $132 $109 $145 $125 $139
a. Calculatex,
s2, and s for the expense data.
In addition, show that the two different formulas for calculating s2
give the same result.

b. Assuming
that the distribution of entertainment expenses is approximately normally
distributed calculate estimates of tolerance intervals containing 68.26
percent, 95.44 percent, and 99.73 percent of all entertainment expenses by the
sales force.

c. If
a member of the sales force submits an entertainment expense (dinner cost for
four) of $190, should this expense be considered unusually high (and possibly
worthy of investigation by the company)?
Explain your answer.
d. Compute
and interpret the z-score for each of the six entertainment expenses.