The following data set represents the age of a random sample of cars on the road today.
The variance of this sample is ________.
A) 9.5
B) 16.4
C) 19.2
D) 23.7
A(n) ________ is a category in a frequency distribution.
A) polygon
B) ogive
C) class
D) histogram
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 95% confidence interval for the regression coefficient for the PEN variable is
________.
A) (“0.998, 0.410)
B) (“2.414, 1.826)
C) (“0.450, “0.138)
D) (“0.361, “0.227)
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 more than 10 minutes after the previous customer?
A) 0.0821
B) 0.1515
C) 0.2732
D) 0.3670
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 one or two
chocolate chips?
A) 0.0596
B) 0.1033
C) 0.1697
D) 0.2020
A random sample of 13 hotels in Boston had an average nightly room rate of $172.10
with a sample standard deviation of $23.90. The 99% confidence interval around this
sample mean is ________.
A) ($151.88, $192.32)
B) ($155.55, $188.65)
C) ($158.86, $185.34)
D) ($165.48, $178.72)
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.
Using α = 0.10, the critical value for this hypothesis test is ________.
A) 2.706
B) 5.991
C) 6.251
D) 7.779
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 of sample information, in thousands of dollars is _________.
A) $10.0
B) $18.0
C) $22.5
D) $25.6
Assume that the number of customers who arrive at a water ice stand follows the
Poisson distribution with an average rate of 6.4 per 30 minutes. What is the probability
that exactly two customers will arrive during the next 15 minutes?
A) 0.0778
B) 0.1510
C) 0.2087
D) 0.4236
The following data represent the discrete probability distribution for the number of stars
that reviewers gave a first edition statistics reference book.
The second edition of this reference book has been released and a random sample of
people that have purchased the book has been collected with the following results.
The publisher would like to know if the probability distribution for reviews has changed
from the first edition to the second edition using α = 0.025. The expected frequency of
three-star reviews is ________.
A) 6
B) 9
C) 12
D) 16
The table below shows the number of cars sold last month by seven employees at
Concord Motors and their number of years of sales experience.
Management would like to use simple regression analysis to estimate monthly car sales
using the number of years of sales experience. The 95% confidence interval that
estimates the average monthly sales for an employee with 5 years of experience is
________.
A) (7.34, 13.12)
B) (9.23, 11.23)
C) (5.73, 14.73)
D) (5.03, 15.43)
An assumption of regression analysis is homoscedasticity,which states that the
A) variation of the dependent variable is the same across all values for the independent
variable.
B) residuals exhibit no patterns across values for the independent variable.
C) residuals exhibit no patterns across values for the dependent variable.
D) relationship between the independent and dependent variables is linear.
The Canadian government would like to test the hypothesis that the standard deviation
for the hourly wage for men is equal to the standard deviation for the hourly wage for
women. The following data summarizes the sample statistics for hourly wages for men
and women.
The test statistic for this hypothesis test would be ________.
A) 1.24
B) 1.61
C) 1.98
D) 2.26
According to the Mortgage Bankers Association, 11% of U.S. mortgages were
delinquent last year. A delinquent mortgage is one that has missed at least one payment
but has not yet gone to foreclosure. A random sample of six mortgages was selected.
What is the probability that exactly one of these mortgages is delinquent?
A) 0.3685
B) 0.3918
C) 0.4461
D) 0.6260
The following table represents the number of minutes that 20 airline passengers had to
wait in order to pass through security along with the frequency in each class.
What is the approximate average number of minutes that a passenger waits to pass
through security?
A) 14.0
B) 15.5
C) 17.0
D) 18.5
Costco Wholesale claims that Costco members prefer its Kirkland brand toilet paper
over the leading national brand. To test this claim, Costco recorded the preferences of a
random sample of customers which are summarized in the table below.
Using α = 0.05, which one of the following statements is true?
A) Because the p-value is greater than α, we reject the null hypothesis and cannot
conclude that Costco customers prefer Kirkland brand toilet paper over the leading
national brand.
B) Because the p-value is greater than α, we fail to reject the null hypothesis and cannot
conclude that Costco customers prefer Kirkland brand toilet paper over the leading
national brand.
C) Because the p-value is less than α, we fail to reject the null hypothesis and conclude
that Costco customers prefer Kirkland brand toilet paper over the leading national
brand.
D) Because the p-value is less than α, we reject the null hypothesis and conclude that
Costco customers prefer Kirkland brand toilet paper over the leading national brand.
Suppose there are 310 first-year lawyers in a particular metropolitan area with an
average starting salary of $156,000 and a standard deviation of $13,000. What is the
standard error of the mean for a random sample of 33 first-year lawyers?
A) $2,142.63
B) $2,263.01
C) $3,145.44
D) $4,512.26
The table below shows the number of cars sold last month by seven employees at
Concord Motors and their number of years of sales experience.
The correlation coefficient for this data is ________.
A) -0.251
B) 0.360
C) 0.553
D) 0.744
The time that customers wait to be served at the delicatessen for a grocery store follows
the uniform distribution between 0 and 7 minutes. What is the standard deviation of this
distribution?
A) 1.16
B) 2.02
C) 3.65
D) 4.10
Sarah is the office manager for a group of financial advisors who provide financial
services for individual clients. She would like to investigate whether a relationship
exists between the number of presentations made to prospective clients in a month and
the number of new clients per month. The following table shows the number of
presentations and corresponding new clients for a random sample of six employees.
Sarah would like to use simple regression analysis to estimate the number of new
clients per month based on the number of presentations made by the employee per
month. The standard error of the slope is ________.
A) 0.2527
B) 0.4622
C) 0.5720
D) 0.6155
Use the following information to answer the question(s) below.
A home appraisal company would like to develop a regression model that would predict
the selling price of a house based on the age of the house in years (Age), the living area
of the house in square feet (Living Area) and the number of bedrooms (Bedrooms). The
following Excel output shows the partially completed regression output from a random
sample of homes that have recently sold.
The multiple coefficient of determination for this model is ________.
A) 0.6439
B) 0.7202
C) 0.7865
D) 0.8486
Use the following information to answer the question(s) below.
A home appraisal company would like to develop a regression model that would predict
the selling price of a house based on the age of the house in years (Age), the living area
of the house in square feet (Living Area) and the number of bedrooms (Bedrooms). The
following Excel output shows the partially completed regression output from a random
sample of homes that have recently sold.
The 95% confidence interval for the regression coefficient for the Bedrooms variable is
________.
A) (-17,502, 80,026)
B) (-8,974, 71,498)
C) (7,036, 55,488)
D) (20,151, 42,373)
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 test statistic for
this sample is ________.
A) 2.213
B) 2.655
C) 6.570
D) 8.069
According to Pew Research Center, 71% of Internet users accessed video-sharing sites
last month. A random sample of 50 Internet users was selected. Using the normal
approximation to the binomial distribution, what is the probability that exactly 36
people from this sample access video-sharing sites?
A) 0.1217
B) 0.2005
C) 0.3669
D) 0.4286
The Centers for Disease Control (CDC) would like to test the hypothesis that the
proportion of obese adults in the U.S. has increased this year when compared to last
year. A random sample of 125 adults this year found that 56 were obese. Last year, a
random sample of 140 adults found that 42 were obese. If Population 1 is defined as
this year and Population 2 is defined as last year, the 98% confidence interval for the
difference in population proportions is ________.
A) (0.089, 0.207)
B) (0.011, 0.285)
C) (“0.029, 0.325)
D) (“0.088, 0.384)
According to market research surveys, HP controls 60% of the color inkjet printer
market in the U.S. A random sample of 120 inkjet users was selected. What is the
probability that 65 or fewer of these individuals used an HP printer?
A) 0.0968
B) 0.1520
C) 0.279
D) 0.3256
Assume that the flight time for a United Airlines flight from Philadelphia to Dallas
follows the uniform probability distribution between 210 and 250 minutes. What is the
probability that a randomly selected flight will take between 220 and 235 minutes?
A) 0.375
B) 0.480
C) 0.557
D) 0.633
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.
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 can reject the null hypothesis and conclude that the
probability distribution does not follow the Poisson distribution with a mean equal to
3.0
B) less than the critical value, we cannot reject the null hypothesis and cannot conclude
that the probability distribution follows the Poisson distribution with a mean equal to
3.0
C) more than the critical value, we cannot reject the null hypothesis and conclude that
the probability distribution does not follow the Poisson distribution with a mean equal
to 3.0
D) less than the critical value, we reject the null hypothesis and cannot conclude that
the probability distribution does not follow the Poisson distribution with a mean equal
to 3.0
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 critical value for this hypothesis test is ________.
A) 5.991
B) 7.851
C) 9.488
D) 11.070
According to R.L. Polk & Co., the average age of cars and light trucks in the U.S. is
10.8 years. Assume that the standard deviation for this population is 3.7 years. A sample
of 35 randomly selected vehicles was selected. What is the probability that the sample
mean will be greater than 10 years?
A) 0.5469
B) 0.7812
C) 0.8997
D) 0.9846
Medicare would like to test the hypothesis that the average monthly rate for
one-bedroom assisted-living facility is equal to $3,300. A random sample of 12
assisted-living facilities had an average rate of $3,690 per month. The standard
deviation for this sample was $530. Medicare would like to set α = 0.05. The p-value
for this hypothesis test would be between ________.
A) 0.01 and 0.02
B) 0.02 and 0.05
C) 0.05 and 0.10
D) 0.10 and 0.20
The average natural gas bill for a random sample of 21 homes in the 19808 zip code
during the month of March was $311.90 with a sample standard deviation of $51.60.
The 90% confidence interval around this sample mean is ________.
A) ($292.46, $331.34)
B) ($285.98, $337.82)
C) ($278.09, $345.71)
D) ($266.82, $356.98)
The Department of Transportation would like to investigate if a difference exists in the
proportion of flights that arrive on-time between Alaska Airlines, Delta Airlines,
Southwest Airlines, and United Airlines. The following data represent the number of
on-time flights from random samples taken from each airline.
The expected frequency of on-time flights from the Delta sample is ________.
A) 66
B) 82.5
C) 90
D) 99
A golfer claims that his median golf score at the course he plays regularly is less than
90. The following random sample from 11 rounds were collected to test this hypothesis.
The correct hypothesis statement for this hypothesis test would be
______________________.
A)
B)
C)
D)