A survey of adults who typically work full-time from home recorded their current
education levels. The results are shown in the table below.
The probability that a randomly selected adult who works from home has less than a
high school diploma is ________.
A) 0.02
B) 0.05
C) 0.17
D) 0.20
Assume that the amount of time that it takes an employee to service a car at an oil
change facility follows the uniform probability distribution between 21 and 38 minutes.
What is the standard deviation of this distribution?
A) 4.91
B) 6.62
C) 9.75
D) 11.89
Comparing the consistency between two data sets when their means are very different is
best done with the _______________.
A) median
B) z-score
C) standard deviation
D) coefficient of variation
Use the following information to answer the question(s) below.
The National Football League has developed a regression model to predict the number
of wins during a season for a team using the following independent variables:
•Average points per game during the season (PPG)
•Average number of penalties committed per game during the season (PEN)
•Turnover differential during the season (TO)
Turnover differential is defined as the number of times the team took the ball away from
their opponent with a turnover minus the number of times the team gave the ball away to
their opponent with a turnover. For example, if TO = +5, the team had five more
takeaways than giveaways. If TO = “7, the team had seven more giveaways than
takeaways during the season.
The following Excel output shows the partially completed regression output from a
random season.
The p-value for the hypothesis test for the overall regression model is ________.
A) 0.0000
B) 0.0005
C) 0.0018
D) 0.4000
“No shows” are the people with reservations who fail to arrive. The following table
shows the number of no shows each day at a hotel over the last 125 business days.
What is the mean number of no shows per day?
A) 0.650
B) 0.952
C) 1.227
D) 1.895
The sample ____________ measures both the direction and strength of the linear
relationship between two variables.
A) variance
B) covariance
C) z-score
D) correlation coefficient
Use the information below to answer the following question(s).
The Marseille Water Taxi ferries tourists from the harbor at Marseille, France, to the
Frioul Islands in the Mediterranean Sea. The table below shows the number of
passengers on the noontime ferry over seven randomly selected days along with the
current ambient temperature in degrees Celsius.
Use the Marseille Water Taxi data to:
A) Calculate the standard error of the slope.
B) Test the significance of the regression slope using α = 0.05.
Sony would like to test the hypothesis that the average age of a PlayStation user is
different from the average age of an Xbox user. A random sample of 36 PlayStation
users had an average age of 34.2 years while a random sample of 30 Xbox users had an
average age of 32.7 years. Assume that the population standard deviation for the age of
PlayStation and Xbox users is 3.9 and 4.0 years, respectively. Sony would like to set α
= 0.10. If Population 1 is defined as PlayStation users and Population 2 is defined as
Xbox users, the test statistic for this hypothesis test would be ________.
A)
B)
C)
D)
A ________ is defined as the probability that the interval estimate will include the
population parameter of interest, such as a mean or a proportion.
A) margin of error
B) confidence level
C) significance level
D) confidence interval
Holiday Inn would like to estimate the satisfaction level of its customers. A sample of
25 hotels were selected and the customers at these locations were asked to rate their
experience on a scale of 1-10. Based on this sample data, Holiday Inn will draw a
conclusion about the satisfaction level of their customers. This is an example of using
_____________.
A) secondary data
B) qualitative data
C) descriptive statistics
D) inferential statistics
Many franchisers favor owners who operate multiple stores by providing them with
preferential treatment. Suppose the Small Business Administration would like to
perform a hypothesis test to investigate if 80% of franchisees own only one location
using α = 0.05. A random sample of 120 franchisees found that 85 owned only one
store. The p-value for this hypothesis test would be ________.
A) 0.0118
B) 0.0320
C) 0.0759
D) 0.1236
A forecasting technique that includes both the trend and seasonality components is
A) weighted moving average.
B) exponential smoothing.
C) exponential smoothing with trend adjustment.
D) multiplicative decomposition.
A respondent of a survey indicates that he owns the home that he currently resides. This
is an example of ____________ data.
A) nominal
B) ordinal
C) interval
D) ratio
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 value with sample information, in thousands of dollars is _________.
A) $212.3
B) $240.0
C) $261.5
D) $258.0
The trend component for a time series with seasonality is found by performing a
regression analysis with
A) the actual time series as the dependent variable and the period number as the
independent variable.
B) the centered-moving-average as the dependent variable and the period number as the
independent variable.
C) the deseasonalized time series as the dependent variable and the period number as
the independent variable.
D) the actual time series as the independent variable and the period number as the
dependent variable.
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 90% confidence interval for the difference in
population means is ________.
A) (“$38.95, $398.95)
B) ($92.42, $267.58)
C) ($136.21, $223.79)
D) ($31.64, $328.36)
AT&T would like to investigate if brand of smartphone and income level are
independent variables. The following contingency table shows the number of customers
who own three brands of smartphones along with their income level.
Using α = 0.05, the conclusion for this hypothesis test would be that because the test
statistic is
_____________________________________________________________________.
A) more than the critical value, we reject the null hypothesis and cannot conclude that
smartphone brand and income level are independent variables
B) more than the critical value, we cannot reject the null hypothesis and can conclude
that smartphone brand and income level are independent variables
C) less than the critical value, we can reject the null hypothesis and conclude that
smartphone brand and income level are independent variables
D) less than the critical value, we cannot reject the null hypothesis and cannot conclude
that smartphone brand and income level are independent variables
Use the information below to answer the following question(s).
The table below shows the number of interceptions thrown during the season by seven
randomly selected National Football League teams and the number of games those
teams won during the season.
Use the NFL team data to:
A) Calculate the coefficient of determination.
B) Interpret the meaning of the coefficient of determination.
C) Test the significance of the coefficient of determination usingα = 0.05.
The purpose of the finite population correction factor for the standard error of the mean
is to reflect the fact that the
_______________________________________________________.
A) population standard deviation is lower for a finite population when compared to an
infinite one
B) sampling error is lower for a finite population when compared to an infinite one
C) population standard deviation is higher for a finite population when compared to an
infinite one
D) sampling error is higher for a finite population when compared to an infinite one
A manufacturer of smartphone batteries will randomly select 20 batteries from the
process each day and count the number of defects. Historically, 4% of the batteries
produced by this company have been defective. The following data represent the
frequency of defective batteries from a random sample of 200 days.
The manufacturer would like to test if the probability distribution for defective batteries
follows the binomial distribution with p = 0.04 and n = 20 using α = 0.05. The expected
number of days from this sample that no batteries from the batch of 20 are defective is
________.
A) 15.08
B) 37.74
C) 71.70
D) 75.48
A marketing research employee randomly selects adults in a shopping mall and asks
them what type of car that they drive. This is an example of using direct observation to
collect data.
YouTube would like to test the hypothesis that the average length of an online video
watched by a user is more than 8 minutes. A random sample of 37 people watched
online videos that averaged 8.7 minutes in length. It is believed that the population
standard deviation for the length of online videos is 2.5 minutes. YouTube would like to
set α = 0.02. The critical value for this hypothesis test would be ________.
A) 2.05
B) 1.96
C) 1.645
D) 1.28
Suppose Bank of America (B of A) would like to investigate if credit score and income
level of an individual are independent of one another. B of A selected a random sample
of 400 adults and asked them to report their credit score range and their income range.
The following contingency table presents these results.
The expected number of individuals with income less than $50,000 and a credit score
between 650 and 750 is ________.
A) 24.0
B) 26.0
C) 32.5
D) 52.0
Hamburgers are on the menu tomorrow at a school cafeteria and the manager needs to
decide how many to have ready for the lunch hour. Each hamburger costs the school
$1.85 and is sold for $3.50. Leftover hamburgers have no monetary value. The manager
expects demand tomorrow to be 100, 150, 200 or 250 hamburgers and would like to
prepare one of these four quantities for lunchtime. If the manager prepares 150
hamburgers and the lunchtime demand is for 200 hamburgers, tomorrow’s profit will be
_________.
A) “$125.50
B) “$20.00
C) $165.00
D) $247.50
The probability of a Type II error is denoted as _______.
A) alpha
B) beta
C) sigma
D) rho
Use the following information to answer the question(s) below.
The National Football League has developed a regression model to predict the number
of wins during a season for a team using the following independent variables:
•Average points per game during the season (PPG)
•Average number of penalties committed per game during the season (PEN)
•Turnover differential during the season (TO)
Turnover differential is defined as the number of times the team took the ball away from
their opponent with a turnover minus the number of times the team gave the ball away to
their opponent with a turnover. For example, if TO = +5, the team had five more
takeaways than giveaways. If TO = “7, the team had seven more giveaways than
takeaways during the season.
The following Excel output shows the partially completed regression output from a
random season.
Every additional point per game will ________________________________.
A) decrease the average number of wins per season by 1.5572
B) decrease the average number of wins per season by 0.3523
C) increase the average number of wins per season by 1.5572
D) increase the average number of wins per season by 0.3523
The Dean of the Business School at State University would like to test the hypothesis
that no difference exists between the average final exam grades for the Introduction to
Marketing course and the Introduction to Finance course. A random sample of eight
students who took both courses was selected and their final exam grades for each
course are shown below.
If Population 1 is defined as the Marketing exam scores and Population 2 is defined as
the Finance exam scores, and using α = 0.05, which one of the following statements is
true?
A) Because the p-value is less than α, we can conclude that a difference exists between
the average final exam grades for the Introduction to Marketing course and the
Introduction to Finance course.
B) Because the p-value is greater than α, we cannot conclude that no difference exists
between the average final exam grades for the Introduction to Marketing course and the
Introduction to Finance course.
C) Because the p-value is less than α, we can conclude that no difference exists between
the average final exam grades for the Introduction to Marketing course and the
Introduction to Finance course.
D) Because the p-value is greater than α, we cannot conclude that a difference exists
between the average final exam grades for the Introduction to Marketing course and the
Introduction to Finance course.
The following data represent a random sample the golf scores for a particular golfer
from a course that he regularly plays.
This golfer would like to test if his golf scores at this course follow the normal
probability distribution with μ = 85.0 and σ = 5.0 using α = 0.05. The conclusion for
this hypothesis test would be that because the test statistic is
____________________________________________.
A) more than the critical value, we cannot reject the null hypothesis and cannot
conclude that the golf scores do not follow the normal probability distribution with μ =
85.0 and σ = 5.0
B) less than the critical value, we cannot reject the null hypothesis and cannot conclude
that the golf scores do not follow the normal probability distribution with μ = 85.0 and
σ = 5.0
C) more than the critical value, we can reject the null hypothesis and conclude that the
golf scores follow the normal probability distribution with μ = 85.0 and σ = 5.0
D) less than the critical value, we cannot reject the null hypothesis and cannot conclude
that the golf scores follow the normal probability distribution with μ = 85.0 and σ = 5.0
According to the IRS, 1.1% of tax returns will be audited next year. A random sample
of 40 tax returns was selected. Use the Poisson distribution to approximate the binomial
distribution to determine the probability that more than two of these tax returns will be
audited.
A) 0.0726
B) 0.1215
C) 0.2067
D) 0.3366
Dempsey’s Garage repairs domestic and import cars. The following table shows the
number of cars that have been serviced by age and type during the last month.
The probability that a randomly selected car from this group was a domestic car or from
0 to under 5 years old is ________.
A) 0.10
B) 0.19
C) 0.60
D) 0.80
Lisa is a regional manager for a restaurant chain that has locations in the towns of
Berwick, Milton, and Leesburg. She would like to investigate if a difference exists in
the proportion of customers who rate their experience as satisfactory or better between
the three locations. The following data represent the number of customers who
indicated they were satisfied from random samples taken at each location.
The chi-square critical value using α = 0.5 is ________.
A) 2.706
B) 3.841
C) 5.991
D) 7.815
The following data represent a sample of games won per season by the San Francisco
49ers of the National Football League over an eight-year period.
13 6 8 7 5 7 4 2
Calculate the median of this sample.
Gartner, Inc. reported that the market share for smartphones is as follows:
To test the validity of Gartner’s report, a random sample of smartphone users was
collected with the following results.
Using α = 0.05, what conclusions can be made about Gartner’s report?
Candy Kitchen sells chocolate nonpareils in 8 oz. containers. Because the candy pieces
are not uniform, the weight of each individual container varies slightly. A random
sample of nine containers was weighed on a precision scale and the results are shown
below:
8.09 8.20 8.03 7.86 7.87 8.06 8.43 7.99 8.08
Determine the percentile of the container that weighs 8.20 oz.
Edmunds.com would like to test the hypothesis that the average age of an imported car
on the road is greater than the average age of a domestic car. The following data shows
the sample size and the average age of cars for import and domestic cars along with the
population standard deviations.
Define Population 1 as import cars and Population 2 as domestic cars and use the
p-value value approach to test this hypothesis with α = 0.05.
Use the information below to answer the following question(s).
The table below shows the number of interceptions thrown during the season by seven
randomly selected National Football League teams and the number of games those
teams won during the season.
Use the NFL team data to calculate the total sum of squares, sum of squares error, and
sum of squares regression.
Use the information below to answer the following question(s).
The table below shows the number of interceptions thrown during the season by seven
randomly selected National Football League teams and the number of games those
teams won during the season.
Use the NFL team data to calculate the 95% prediction interval for the number of wins
for a team that throws 14 interceptions during the season.
Organizations are relying more and more on social-networking sites to research job
candidates. According to CareerBuilder, 52% of organizations do not use these sites. A
random sample of 150 organizations found that 67 of them do not use
social-networking sites to research job candidates. Use the p-value approach to test the
hypothesis that less than 52% of organizations do not use social-networking sites to
research job candidates with α = 0.01.
Use the following information to answer the question(s) below.
Suppose CitiMortgage would like to develop a regression model that would predict a
person’s credit score based on their age, weekly income, years living in their current
residence, and gender (Male = 0, Female = 1). The following data represent the values
for the independent and dependent variables from a random sample of adults.
Perform a best subsets regression for the CitiMortgage data using the independent
variables that do not exhibit multicollinearity. Interpret the meaning of the regression
coefficients for the final model.
