The following data represents the number of Sony TVs sold per day at a particular
Costco over a random sample of five business days.
The standard deviation of this sample is ________.
A) 1.2
B) 1.5
C) 2.0
D) 2.6
Which of the following is an example of quantitative data?
A) the zip code of your home address
B) Apple’s closing stock price today
C) your gender
D) your telephone number
A random sample of 25 roundtrip flights between Philadelphia and Dallas has an
average airfare of $393.50 with a sample standard deviation of $50.30. The 95%
confidence interval around this sample mean is ________.
A) ($372.74, $414.26)
B) ($383.44, $403.56)
C) ($353.26, $433.74)
D) ($388.47, $398.53)
Expedia would like to test the hypothesis that the average roundtrip airfare between
Philadelphia and Paris is higher for a flight originating in Philadelphia when compared
to a flight originating in Paris. The following data summarizes the sample statistics for
roundtrip flights originating in both cities. Assume that the population variances are
equal.
If Population 1 is defined as flights originating in Philadelphia and Population 2 is
defined as flights originating in Paris, the correct hypothesis statement for this
hypothesis test would be ____________________________.
A)
B)
C)
D)
A ________ is a table that shows the number of data observations that fall into specific
intervals.
A) histogram
B) frequency distribution
C) percent polygon
D) Pareto chart
Sony would like to test the hypothesis that the standard deviation for the age of
PlayStation users is higher than the standard deviation for the age of Xbox users. The
following table summarizes sample statistics from each population.
Using α = 0.05, the critical value for this hypothesis test would be ________.
A) 1.906
B) 1.930
C) 1.964
D) 2.028
You have been assigned to test the hypothesis that the variability for the number of
hours per week that an American works is equal to the variability for the number of
hours per week that a Swede works. The following data summarizes the sample
statistics for the number of hours worked per week for workers in each country.
Using α = 0.10, the conclusion for this hypothesis test would be that because the test
statistic is _______________________________.
A) more than the critical value, we fail to reject the null hypothesis and conclude that
the variability for the number of hours per week that an American works is not equal to
the variability for the number of hours per week that a Swede works
B) more than the critical value, we reject the null hypothesis and can conclude that the
variability for the number of hours per week that an American works is not equal to the
variability for the number of hours per week that a Swede works
C) less than the critical value, we fail to reject the null hypothesis and cannot conclude
that the variability for the number of hours per week that an American works is not
equal to the variability for the number of hours per week that a Swede works
D) less than the critical value, we fail to reject the null hypothesis and conclude that the
variability for the number of hours per week that an American works is equal to the
variability for the number of hours per week that a Swede works
During the 3 pm to 5 pm time period, cars arrive at a bank’s drive-through window at an
average rate of 15 customers per hour. Assume that the time between arrivals follows
the exponential distribution. What is the probability that a randomly selected customer
will arrive between 2 and 6 minutes after the previous customer?
A) 0.0560
B) 0.1776
C) 0.2395
D) 0.3834
The following data show the monthly rental for a random sample of one-bedroom
apartments in York, Pennsylvania.
Construct a histogram for this data.
An office building has four copier machines that require the administrative assistant to
replenish the paper supply when the paper bin is empty. It is believed that the need for
paper for a copier on any given day follows the binomial distribution with p = 0.50. The
following data represent the number of days that 0, 1, 2, 3, or 4 copiers needed paper
replenished from a random sample of 100 business days.
The expected number of days from this sample that all four copiers needed to be
replenished is ________.
A) 6.25
B) 15.5
C) 18.25
D) 25.0
A retail chain would like to test if a difference exists between the variability of
customer satisfaction scores from two locations. The following data represents
satisfaction scores from a random sample of customers from these locations on a scale
of 1-20.
The variance for the satisfaction scores at Location 2 would be ________.
A) 2.00
B) 3.29
C) 4.75
D) 6.81
During the 2013 Major League Baseball season, the St. Louis Cardinals averaged
41,602 fans per home game. Suppose attendance during the season follows the normal
probability distribution with a standard deviation of 9,440 per game. What is the
probability that a randomly selected game during the 2013 season had an attendance
between 25,000 and 35,000 people?
A) 0.2028
B) 0.3655
C) 0.4218
D) 0.5860
The following chart shows the average number of hours commuters spend in traffic
delays per year at the six most congested cities in the U.S.
This chart is an example of a ____________ chart.
A) stacked bar
B) horizontal bar
C) Pareto
D) vertical bar
The ________ measures the amount of dispersion of observed data around a regression
line.
A) correlation coefficient
B) coefficient of determination
C) standard error of the slope
D) standard error of the estimate
The least squares method will minimize the sum of squares _______ when describing
the equation that best fits the ordered pairs.
A) error
B) regression
C) between
D) within
The following data represent the end-of-month stock price of Facebook rounded to the
nearest dollar from June to December.
The trend projection slope for this data is ________.
A) -1.3555
B) -2.3903
C) 4.2143
D) 6.0952
Sheridan Motors is a car dealership that would like to investigate if there is a difference
in the average number of car sales per month between three sales employees using a
randomized block ANOVA. The following data represent the number of car sales last
year for these employees for six different months.
The total sum of squares for these observations is ________.
A) 91.0
B) 93.5
C) 101.7
D) 126.5
The probability of winning a 5/25 lottery game where 5 numbers are picked from a
range of 25 is ________.
A) 1/32,852
B) 1/53,130
C) 1/353,775
D) 1/6,375,600
A company that bakes chocolate chip cookies averages 5.2 chocolate chips per cookie.
Assume that the number of chocolate chips per cookie follows the Poisson distribution.
What is the probability that a randomly selected cookie will contain exactly four
chocolate chips?
A) 0.1681
B) 0.2254
C) 0.2960
D) 0.3325
Consider the partially completed two-way ANOVA summary table.
The number of Factor B populations being compared for this ANOVA procedure is
_____
A) 2
B) 3
C) 4
D) 5
When testing for a normal distribution with the chi-square goodness-of-fit test with a
sample size of 100 observations, the number of intervals needed to satisfy the minimum
number of expected frequencies is ________.
A) 4
B) 5
C) 6
D) The sample size is too small to perform the chi-square goodness-of-fit test.
According to the Centers for Medicare & Medicaid Services, 21% of nursing homes in
the United States received five stars in overall ratings on a scale of 1 to 5. A random
sample of seven nursing homes was selected. What is the probability that more than one
of them received five stars?
A) 0.0681
B) 0.1165
C) 0.1717
D) 0.4506
State University offers several sections of a Business Statistics course in an in-class and
online format. Both formats are administered the same final exam each year. You have
been assigned to test the hypothesis that the average final exam score of in-class
students is different from the average final exam score of online students. The following
data summarizes the sample statistics for the final exam scores for students from each
format. Assume that the population variances are unequal.
If Population 1 is defined as in-class format and Population 2 is defined as online
format, the degrees of freedom for this hypothesis test are ________.
A) 44
B) 45
C) 46
D) 47
The following data represents the ages of a household that consists of five people.
The range of this data set is ________.
A) 2
B) 7
C) 12
D) 32
The class ________ is the breadth, or range, of numbers we plan to put into each class
of a frequency distribution using grouped quantitative data.
A) boundary
B) frequency
C) width
D) number
Use the following information to answer the question(s) below.
Ford would like to develop a regression model that would predict the number of cars
sold per month by a dealership employee based on the employee’s number of years of
sales experience (Exp), the employee’s weekly base salary before commissions (Salary),
and the education level of the employee. There are three levels of education in the sales
forcehigh school degree, associate’s degree, and bachelor’s degree. The following
dummy variables have been defined.
The following Excel output shows the partially completed regression output from a
random sample of employees from the previous month.
The mean square regression for this model is ________.
A) 3.01
B) 60.23
C) 66.90
D) 267.61
Use the information below to answer the following question(s).
Hats-R-Us would like to produce a new design of hats for the upcoming Major league
Baseball World Series. They need to decide to produce a large quantity or small
quantity of hats prior to the event starting. Eventual demand for this new design will be
strong or weak with a 50/50 chance of each level occurring. The following table shows
the payoff for each combination of production size and demand level, in thousands of
dollars.
Hats-R-Us also has the option of conducting a market survey at a cost of $10,000 to
acquire more accurate information about the likelihood of each demand level. If the
survey results are positive, there is an 83% probability that the eventual demand for the
new hat design will be strong. If the survey results are negative, there is a 23%
probability that the eventual demand for the new hat design will be strong.
Construct a decision tree to answer the following set of questions.
The expected monetary value, in thousands of dollars, for a small production quantity if
Hats-R-Us conducts a market survey and the survey results are positive is _________.
A) $156.2
B) $286.0
C) $350.7
D) $522.7
Consider the partially completed randomized block ANOVA summary table.
The blocking factor F-test statistic for this ANOVA procedure is ________.
A) 3.20
B) 4.00
C) 5.16
D) 6.70
A chocolate chip cookie producer claims that its cookies average 3 chocolate chips and
that the distribution follows the Poisson. A consumer group wanted to test this claim
and randomly sampled 150 cookies. The resulting frequency distribution is shown
below.
The expected number of cookies from this sample that will exactly five chips is
________.
A) 15.12
B) 19.32
C) 23.60
D) 26.17
AutoTrader.com would like to test if a difference exists in the age of three different
types of vehicles currently on the road–trucks, cars, and vans. The following data
represent the age of a random sample of trucks, cars, and vans.
The mean square between for these observations is________.
A) 2.0
B) 4.7
C) 5.5
D) 16.0
AutoTrader.com would like to test if a difference exists in the age of three different
types of vehicles currently on the road–trucks, cars, and vans. The following data
represent the age of a random sample of trucks, cars, and vans.
The mean squares within for these observations is ________.
A) 3.3
B) 6.5
C) 7.3
D) 9.0
Porter Automotive is a car dealership that sells Buicks and Hondas. The following data
shows the number of buyers this month according to the brand of car they purchased as
well as their age group.
The percentage of buyers who are under 40 years old in this data is _____.
A) 20%
B) 46%
C) 50%
D) 54%
A beach community on a barrier island has three real estate companies that list rental
properties by location which are classified as ocean-front, beach-block, or mid-island.
The following contingency table shows the number of properties listed by each
company along with their location.
The test statistic for this sample is ________.
A) 1.511
B) 3.795
C) 8.447
D) 10.254
Note: The problems below are based on the following information:
Chris, Steve, and Josh routinely play golf together and would like to know if the
average number of golf balls lost during a round differs between them. The following
table shows the number of golf balls lost by each player during a random sample of golf
rounds.
Perform a one-way ANOVA using α = 0.01 to determine if a difference exists in the
average number of golf balls lost during a round among these three players.
A business school at a particular university has 25 full-time faculty. The following table
shows the number of faculty grouped by years of teaching experience.
What is the approximate average years of teaching experience for this population?
The following table shows the number of car accidents reported each day in a particular
city over the last 50 days.
What is the mean number of accidents per day?
An HP inkjet printer ad advertises that the black ink cartridge will provide enough ink
for an average of 270 pages. Assume that the standard deviation for this population is
16.5 pages. A random sample of 40 customers was surveyed about the number of pages
they were able to print with their black ink cartridges. The sample average was 268.1
pages. Use a 95% confidence interval to test the validity of HP’s claim.
The Department of Transportation would like to test the hypothesis that the standard
deviation for the age of cars on the road is less than 4.0 years. A sample of 21 cars was
randomly selected and their ages were recorded. The standard deviation for the age of
these cars was found to be 2.7 years. Test this hypothesis using α = 0.05.
Consumer Reports would like to conduct a hypothesis test to determine if the average
battery life for an iPad is different from the average battery life for a Kindle Fire. The
following data represents the battery life from a random sample of iPads and Kindle
Fires in hours. Assume that the population variances are equal.
Define Population 1 as iPads and Population 2 as Kindles and use the critical value
approach to test this hypothesis with α = 0.02.
Traveler’s Insurance would like to test the hypothesis that the average number of miles
driven per month by a male teenage driver exceeds the average number of miles driven
per month by a female teenage driver by more than 50 miles. The following data
summarizes the sample statistics for the miles driven per month by each gender.
Assume that the population variances are equal.
Define Population 1 as male drivers and Population 2 as female drivers and use the
critical value approach to test this hypothesis with α = 0.05.
The following table shows the number of points scored by the Green Bay Packers and
the Detroit Lions of the National Football League over 15 recent seasons.
Use four classes, each with a class width of 100. Start classes with 201-300, 301-400,
and so on, and construct a cumulative percentage polygon. What conclusions can you
draw comparing these two teams?
Use the following information to answer the question(s) below.
The following data provides the monthly Comcast cable bill for a random sample of 20
households along with the number of televisions in the household (TV), the number of
people living in the household (People), and the number of years that household has
been a Comcast customer (Years).
Interpret the meaning of the regression coefficients for the Comcast cable bill model.
