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True or False: The p chart is a control chart used for monitoring the proportion of items
that meet given specifications.
TABLE 8-9
A university wanted to find out the percentage of students who felt comfortable
reporting cheating by their fellow students. A survey of 2,800 students was conducted
and the students were asked if they felt comfortable reporting cheating by their fellow
students. The results were 1,344 answered "Yes" and 1,456 answered "No."
True or False: Referring to Table 8-9, the parameter of interest is the total number of
students in the population who feel comfortable reporting cheating by their fellow
students.
True or False: TABLE 17-9
What are the factors that determine the acceleration time (in sec.) from 0 to 60 miles per
hour of a car? Data on the following variables for 171 different vehicle models were
collected:
Accel Time: Acceleration time in sec.
Cargo Vol: Cargo volume in cu. ft.
HP: Horsepower
MPG: Miles per gallon
SUV: 1 if the vehicle model is an SUV with Coupe as the base when SUV and Sedan
are both 0
Sedan: 1 if the vehicle model is a sedan with Coupe as the base when SUV and Sedan
are both 0
The regression results using acceleration time as the dependent variable and the
remaining variables as the independent variables are presented below.
The various residual plots are as shown below.
The coefficient of partial determination ( ) of each of the 5
predictors are, respectively, 0.0380, 0.4376, 0.0248, 0.0188, and 0.0312.
The coefficient of multiple determination for the regression model using each of the 5
variables Xj as the dependent variable and all other X variables as independent variables
( ) are, respectively, 0.7461, 0.5676, 0.6764, 0.8582, 0.6632.
Referring to Table 17-9, the 0 to 60 miles per hour acceleration time of a sedan is
predicted to be 0.6427 seconds higher than that of an SUV.
True or False: TABLE 17-12
The marketing manager for a nationally franchised lawn service company would like to
study the characteristics that differentiate home owners who do and do not have a lawn
service. A random sample of 30 home owners located in a suburban area near a large
city was selected; 15 did not have a lawn service (code 0) and 15 had a lawn service
(code 1). Additional information available concerning these 30 home owners includes
family income (Income, in thousands of dollars), lawn size (Lawn Size, in thousands of
square feet), attitude toward outdoor recreational activities (Attitude 0 = unfavorable, 1
= favorable), number of teenagers in the household (Teenager), and age of the head of
the household (Age).
The Minitab output is given below:
Referring to Table 17-12, there is not enough evidence to conclude that Income makes
a significant contribution to the model in the presence of the other independent
variables at a 0.05 level of significance.
True or False: The answer to the question "What is your favorite color?" is an example
of an ordinal scaled variable.
True or False: CPL > 1 implies that the process mean is more than 3 standard deviations
away from the lower specification limit.
True or False: TABLE 17-5
You worked as an intern at We Always Win Car Insurance Company last summer. You
notice that individual car insurance premiums depend very much on the age of the
individual, the number of traffic tickets received by the individual, and the population
density of the city in which the individual lives. You performed a regression analysis in
EXCEL and obtained the following information:
Referring to Table 17-5, the multiple regression model is significant at a 10% level of
significance.
TABLE 11-8
An important factor in selecting database software is the time required for a user to
learn how to use the system. To evaluate three potential brands (A, B and C) of database
software, a company designed a test involving five different employees. To reduce
variability due to differences among employees, each of the five employees is trained
on each of the three different brands. The amount of time (in hours) needed to learn
each of the three different brands is given below:
Below is the Excel output for the randomized block design:
True or False: Referring to Table 11-8, there is evidence of a significant difference in
the mean amount of time needed to learn Brand A and Brand C at the 5% level of
significance.
TABLE 3-1
Health care issues are receiving much attention in both academic and political arenas. A
sociologist recently conducted a survey of citizens over 60 years of age whose net
worth is too high to qualify for Medicaid. The ages of 25 senior citizens were as
follows:
Referring to Table 3-1, identify which of the following is the correct statement.
A) One fourth of the senior citizens sampled are below 64 years of age.
B) The middle 50% of the senior citizens sampled are between 65.5 and 73.0 years of
age.
C) 25% of the senior citizens sampled are older than 81.5 years of age.
D) All of the above are correct.
TABLE 13-2
A candy bar manufacturer is interested in trying to estimate how sales are influenced by
the price of their product. To do this, the company randomly chooses 6 small cities and
offers the candy bar at different prices. Using candy bar sales as the dependent variable,
the company will conduct a simple linear regression on the data below:
Referring to Table 13-2, what is for these data?
A) 0
B) 1.66
C) 2.54
D) 25.66
According to the Chebyshev rule, at least what percentage of the observations in any
data set are contained within a distance of 2 standard deviations around the mean?
A) 67%
B) 75%
C) 88.89%
D) 95%
TABLE 6-7
A company has 125 personal computers. The probability that any one of them will
require repair on a given day is 0.15.
Referring to Table 6-7, which of the following is one of the properties required so that
the binomial distribution can be used to compute the probability that no more than 2
computers will require repair on a given day?
A) The probability that a computer that will require repair in the morning is the same as
that in the afternoon.
B) The number of computers that will require repair in the morning is independent of
the number of computers that will require repair in the afternoon.
C) The probability that any one of the computers that will require repair on a given day
will not affect or change the probability that any other computers that will require repair
on the same day.
D) The probability that two or more computers that will require repair in a given day
approaches zero.
TABLE 6-1
The number of column inches of classified advertisements appearing on Mondays in a
certain daily newspaper is normally distributed with a population mean of 320 and a
population standard deviation of 20 inches.
Referring to Table 6-1, a single Monday is chosen at random. State in which of the
following ranges the number of column inches of classified advertisement is most likely
to be
A) 300-320.
B) 310-330.
C) 320-340.
D) 330-350.
TABLE 1-3
The manager of the customer service division of a major consumer electronics company
is interested in determining whether the customers who have purchased a Blu-ray
player made by the company over the past 12 months are satisfied with their products.
Referring to Table 1-3, which of the following questions in the survey will not likely
induce a measurement error?
A) How many times have you illegally copied copyrighted sporting events?
B) What is your exact annual income?
C) How many times have you brought the Blu-ray player back for service?
D) How many times have you failed to set the time on the Blu-ray player?
TABLE 1-3
The manager of the customer service division of a major consumer electronics company
is interested in determining whether the customers who have purchased a Blu-ray
player made by the company over the past 12 months are satisfied with their products.
Referring to Table 1-3, the manager decides to ask a sample of customers, who have
bought a Blu-ray player made by the company and filed a complaint over the past year,
to fill in a survey about whether they are satisfied with the product. This method will
most likely suffer from
A) nonresponse error.
B) measurement error.
C) coverage error.
D) non-probability sampling.
If you want to recover the trend using exponential smoothing, you will choose a weight
(W) that falls in the range
A) [0,0.2].
B) [0.2,0.4].
C) [0.6,0.8].
D) [0.9,1.0].
A supplier of silicone sheets for producers of computer chips wants to evaluate her
manufacturing process. She takes sample sizes of 5 from each day's output and counts
the number of blemishes on each silicone sheet for 20 days consecutive days. Which of
the following would be the most appropriate analysis to perform?
A) Autoregressive modeling
B) Exponential smoothing
C) Multiple linear regression
D) Construct a c chart
The portfolio expected return of two investments
A) will be higher when the covariance is zero.
B) will be higher when the covariance is negative.
C) will be higher when the covariance is positive.
D) does not depend on the covariance.
TABLE 4-2
An alcohol awareness task force at a Big-Ten university sampled 200 students after the
midterm to ask them whether they went bar hopping the weekend before the midterm or
spent the weekend studying, and whether they did well or poorly on the midterm. The
following result was obtained.
Referring to Table 4-2, the events "Did Well on Midterm" and "Did Poorly on Midterm"
are
A) dependent.
B) mutually exclusive.
C) collectively exhaustive.
D) All of the above.
If a categorical independent variable contains 4 categories, then ________ dummy
variable(s) will be needed to uniquely represent these categories.
A) 1
B) 2
C) 3
D) 4
TABLE 12-1
A corporation randomly selects 150 salespeople and finds that 66% who have never
taken a self-improvement course would like such a course. The firm did a similar study
10 years ago in which 60% of a random sample of 160 salespeople wanted a
self-improvement course. The groups are assumed to be independent random samples.
Let and represent the true proportion of workers who would like to attend a
self-improvement course in the recent study and the past study, respectively.
Referring to Table 12-1, what is the critical value when testing whether the population
proportions are different if = 0.10?
A) 1.645
B) 1.96
C) 3.842
D) 2.706
Which of the following methods should not be used for short-term forecasts into the
future?
A) Exponential smoothing
B) Moving averages
C) Linear trend model
D) Autoregressive modeling
An airline wants to select a computer software package for its reservation system. Four
software packages (1, 2, 3, and 4) are commercially available. An experiment is set up
in which each package is used to make reservations for 5 randomly selected weeks and
data on the number of passengers that are bumped over a month are collected. (A total
of 20 weeks was included in the experiment.) The variance on the number of passengers
that are bumped is found to be roughly the same for the 4 packages. Which of the
following tests will be the most appropriate to find out if the mean number of
passengers being bumped over a month is the same across the 4 packages?
A) Paired t test
B) Pooled-variance t test
C) One-way ANOVA F test for differences among more than two means
D) Two-way ANOVA F test for interaction effect
A physician and president of a Tampa Health Maintenance Organization (HMO) are
attempting to show the benefits of managed health care to an insurance company. The
physician believes that certain types of doctors are more cost-effective than others. To
investigate this, the president obtained independent random samples of 20 HMO
physicians from each of 4 primary specialties - General Practice (GP), Internal
Medicine (IM), Pediatrics (PED), and Family Physicians (FP) - and recorded the total
charges per member per month for each. A second variable which the president believes
influences total charges per member per month is whether the doctor is a foreign or
USA medical school graduate. To investigate this, the president also collected data on
20 foreign medical school graduates in each of the 4 primary specialty types described
above. Altogether, information on charges for 40 doctors (20 foreign and 20 USA
medical school graduates) was obtained for each of the 4 specialties. Which of the
following tests will be the most appropriate to find out if the primary specialty and the
origin of medical school degree interact to affect the charges?
A) Tukey-Kramer multiple comparisons procedure for one-way ANOVA
B) One-way ANOVA F test for differences among more than two means
C) One-way ANOVA F test for interaction effect
D) Two-way ANOVA F test for interaction effect
TABLE 9-9
The president of a university claimed that the entering class this year appeared to be
larger than the entering class from previous years but their mean SAT score is lower
than previous years. He took a sample of 20 of this year's entering students and found
that their mean SAT score is 1,501 with a standard deviation of 53. The university's
record indicates that the mean SAT score for entering students from previous years is
1,520. He wants to find out if his claim is supported by the evidence at a 5% level of
significance.
Referring to Table 9-9, the parameter the president is interested in is
A) the mean number of entering students to his university this year.
B) the mean number of entering students to all U.S. universities this year.
C) the mean SAT score of the entering students to his university this year.
D) the mean SAT score of the entering students to all U.S. universities this year.
The amount of juice that can be squeezed from a randomly selected orange out of a box
of oranges with approximately the same size can most likely be modeled by which of
the following distributions?
A) Uniform distribution
B) Poisson distribution
C) Normal distribution
D) Exponential distribution
The difference between expected payoff under certainty and expected value of the best
act without certainty is the
A) expected monetary value.
B) expected net present value.
C) expected value of perfect information.
D) expected rate of return.
A manager of the credit department for an oil company would like to determine whether
the mean monthly balance of credit card holders is equal to $75. An auditor selects a
random sample of 100 accounts and finds that the mean owed is $83.40 with a sample
standard deviation of $23.65. If you were to conduct a test to determine whether the
auditor should conclude that there is evidence that the mean balance is different from
$75, which test would you use?
A) Z test of a population mean
B) Z test of a population proportion
C) t test of population mean
D) t test of a population proportion
TABLE 16-4
The number of cases of merlot wine sold by a Paso Robles winery in an 8-year period
follows.
Referring to Table 16-4, exponential smoothing with a weight or smoothing constant of
0.2 will be used to forecast wine sales. The forecast for 2013 is ________.
Referring to Table 14-19, what is the estimated odds ratio for a home
owner with a family income of $50,000 and a lawn size of 5,000
square feet?
TABLE 14-19
The marketing manager for a nationally franchised lawn service
company would like to study the characteristics that differentiate
home owners who do and do not have a lawn service. A random
sample of 30 home owners located in a suburban area near a large
city was selected; 11 did not have a lawn service (code 0) and 19 had
a lawn service (code 1). Additional information available concerning
these 30 home owners includes family income (Income, in thousands
of dollars) and lawn size (Lawn Size, in thousands of square feet).
The PHStat output is given below:
TABLE 12-3
The director of transportation of a large company is interested in the usage of her van
pool. She considers her routes to be divided into local and non-local. She is particularly
interested in learning if there is a difference in the proportion of males and females who
use the local routes. She takes a sample of a day's riders and finds the following:
She will use this information to perform a chi-square hypothesis test using a level of
significance of 0.05.
Referring to Table 12-3, the expected cell frequency in the Female/Non-Local cell is
________.
TABLE 17-12
The marketing manager for a nationally franchised lawn service company would like to
study the characteristics that differentiate home owners who do and do not have a lawn
service. A random sample of 30 home owners located in a suburban area near a large
city was selected; 15 did not have a lawn service (code 0) and 15 had a lawn service
(code 1). Additional information available concerning these 30 home owners includes
family income (Income, in thousands of dollars), lawn size (Lawn Size, in thousands of
square feet), attitude toward outdoor recreational activities (Attitude 0 = unfavorable, 1
= favorable), number of teenagers in the household (Teenager), and age of the head of
the household (Age).
The Minitab output is given below:
Referring to Table 17-12, what are the degrees of freedom for the chi-square
distribution when testing whether the model is a good-fitting model?
There are only 4 empty rooms available in a student dormitory for eleven new
freshmen. Each room is considered unique so that it matters who is being assigned to
which room. How many different ways can those 4 empty rooms be filled, one student
per room?
TABLE 7-6
Online customer service is a key element to successful online retailing. According to a
marketing survey, 37.5% of online customers take advantage of the online customer
service. Random samples of 200 customers are selected.
Referring to Table 7-6, 90% of the samples proportions symmetrically around the
population proportion will have between ________% and ________% of the customers
who take advantage of online customer service.
TABLE 7-8
According to a survey, only 15% of customers who visited the website of a major retail
store made a purchase. Random samples of size 50 are selected from a population of
900. Use the finite population correction factor.
Referring to Table 7-8, what proportion of the samples will have between 20% and 30%
of customers who will make a purchase after visiting the website?
TABLE 3-6
The rate of return of an Internet Service Provider over a 10-year period are: 10.25%,
12.64%, 8.37%, 9.29%, 6.23%, 42.53%, 29.23%, 15.25%, 21.52%, -2.35%.
Referring to Table 3-6, construct a boxplot for the rate of return.
TABLE 18-9
The manufacturer of canned food constructed control charts and analyzed several
quality characteristics. One characteristic of interest is the weight of the filled cans. The
lower specification limit for weight is 2.95 pounds. The table below provides the range
and mean of the weights of five cans tested every fifteen minutes during a day's
production.
Referring to Table 18-9, construct an chart for the weight.
