Expedia would like to test the hypothesis that the proportion of Southwest Airline
flights that arrive on-time is less than 0.90. A random sample of 140 United Airline
flights found that 119 arrived on-time. Expedia would like to set α = 0.05. The p-value
for this hypothesis test would be ________.
A) 0.0137
B) 0.0244
C) 0.0664
D) 0.0872
The goal of constructing a frequency distribution is to identify a useful pattern in the
data and often there is more than one acceptable way to accomplish this with grouped
quantitative data.
The following data shows the number of home runs hit by the top 12 home run hitters
during a recent Major League Baseball season.
The interquartile range is ________.
A) 4
B) 4.5
C) 5.5
D) 7
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 median of this sample is ________.
A) 4.0
B) 5.2
C) 7.0
D) 8.0
Sony would like to test the hypothesis that the median age of a PlayStation user is
different from the median age of an Xbox user. The following table shows the ages of a
random sample of PlayStation and Xbox users.
Using α = 0.05, which one of the following statements is true?
A) Because the test statistic is greater than the upper critical value, we conclude that
there is a difference in the median ages of PlayStation and Xbox users.
B) Because the test statistic is greater than the upper critical value, we cannot conclude
that there is a difference in the median ages of PlayStation and Xbox users.
C) Because the test statistic is between the lower and the upper critical values, we
conclude that there is a difference in the median ages of PlayStation and Xbox users.
D) Because the test statistic is between the lower and the upper critical values, we
cannot conclude that there is a difference in the median ages of PlayStation and Xbox
users.
Use the information below to answer the following question(s).
Cape May Realty manages rental beach properties during the summer season for
property owners. They would like to determine if a relationship exists between the
square footage of beach property and the weekly rental rates during the summer season.
Simple regression analysis was performed using a random sample of beach properties
with the results shown below.
According to these regression results, the average weekly rental for a property that is
2,000 square feet is ________.
A) $1,219
B) $1,473
C) $1,598
D) $1,750
In Delaware, cars are inspected each year using state-operated inspection centers. The
Wilmington center has three drive-through lanes where cars are inspected in a sequence
of steps. The following data show the number of minutes that a random sample of
drivers spent waiting and having their cars inspected in the three lanes each day of the
week.
The state of Delaware would like to perform a randomized block ANOVA to test for a
difference in the average times the drivers spend in the three lanes using the weekday as
a blocking factor with α = 0.05. The mean square between for these observations is
________.
A) 80.5
B) 90.6
C) 98.3
D) 110.5
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 five customers will arrive during the next 30 minutes?
A) 0.0215
B) 0.0943
C) 0.1487
D) 0.3070
The pH scale measures the amount of alkalinity or acidity in a liquid and ranges from
0-14. The ideal pH for a swimming pool is 7.2. A pH that is too high or low can cause
discomfort for the swimmers, especially in the eyes. High variability in the pH readings
across the swimming pool can be problematic. The following data shows seven pH
readings that were taken at the Wilson Community Pool from different locations at 10
a.m. this morning.
The pool management would like to test the hypothesis that the standard deviation of
the pH readings across the pool is less than 0.40. The correct hypothesis statement
would be _________.
A)
B)
C)
D)
The pH scale measures the amount of alkalinity or acidity in a liquid and ranges from
0-14. The ideal pH for a swimming pool is 7.2. A pH that is too high or low can cause
discomfort for the swimmers, especially in the eyes. High variability in the pH readings
across the swimming pool can be problematic. The following data shows seven pH
readings that were taken at the Wilson Community Pool from different locations at 10
a.m. this morning.
The pool management would like to test the hypothesis that the standard deviation of
the pH readings across the pool is less than 0.40. 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 fail to reject the null hypothesis and cannot conclude
that the standard deviation of the pH readings across the pool is less than 0.40
B) less than the critical value, we can reject the null hypothesis and conclude that the
standard deviation of the pH readings across the pool is less than 0.40
C) less than the critical value, we fail to reject the null hypothesis and cannot conclude
that the standard deviation of the pH readings across the pool is less than 0.40
D) more than the critical value, we can reject the null hypothesis and conclude that the
standard deviation of the pH readings across the pool is less than 0.40
If the main factor for randomized block ANOVA is statistically significant, you should
___________________.
A) reject the null hypothesis for the main factor and proceed with your conclusions
B) perform a hypothesis test on the blocking factor to check for a difference in blocking
means
C) perform a hypothesis test on the main factor using one-way ANOVA
D) perform a hypothesis test on the main factor using two-way ANOVA
The airline industry defines no-shows as passengers who have purchased a ticket but
fail to arrive at the gate on time for departure. Southwest Airlines operates many flights
from Philadelphia to Dallas and experienced the following no-show probability
distribution last year.
The following data represent the number of no-shows that occurred on a random sample
of 120 flights between these two cities this year.
Southwest Airlines would like to know if the probability distribution of no-shows has
changed between last year and this year on flights between these two cities using α =
0.05. The expected frequency of five no-shows for this sample is ________.
A) 13.2
B) 17.0
C) 20.7
D) 22.2
The critical value for an 84% confidence interval for the proportion is ________.
A) 1.00
B) 1.41
C) 1.96
D) 2.65
Susan would like to conduct a survey of homeowners in the Meadowbrook
neighborhood to get their opinions on proposed road modifications in the area. Which
of the following is an example of a stratified sample?
A) Susan randomly chooses two streets in the neighborhood and selects every home on
these streets.
B) Susan selects the first 20 homes that she passes as she walks into the entrance of the
neighborhood.
C) Susan selects every third house on each street in the neighborhood.
D) Susan ensures that her sample contains a number of two-story, split-level, and ranch
homes in her sample that corresponds to the number of homes in the neighborhood.
The following graph shows the curb weight of seven cars, in pounds, along with their
corresponding highway miles per gallon.
Which one of the following statements is correct?
A) Curb weight is the dependent variable in the graph.
B) Miles per gallon is the independent variable in the graph.
C) As the curb weight increases, the highway miles per gallon tend to decrease.
D) As the curb weight increases, the highway miles per gallon tend to increase.
________ data has the benefit of a true zero point.
A) Nominal
B) Ordinal
C) Interval
D) Ratio
Experian would like to test the hypothesis that the average credit score for an adult in
Virginia is different from the average credit score for an adult in North Carolina. A
random sample of 40 adults in Virginia had an average credit score of 699 and a random
sample of 35 adults in North Carolina had an average credit score of 682. It is believed
that the population standard deviation for credit scores is 44 and 41 for Virginia and
North Carolina residents, respectively. Experian would like to set α = 0.05. Define
Population 1 as Virginia and Population 2 as North Carolina. Construct a 95%
confidence interval for the difference in population mean and interpret the results.
Expedia would like to test the hypothesis that the proportion of Southwest Airline
flights that arrive on-time is less than 0.90. A random sample of 140 United Airline
flights found that 119 arrived on-time. Expedia would like to set α = 0.05. The test
statistic for this hypothesis test would be ________.
A) .
B) .
C) .
D) .
The following data show the monthly rental for a random sample of one-bedroom
apartments in York, Pennsylvania.
Construct a relative frequency distribution for this data and determine the probability a
randomly selected one-bedroom apartment will rent between $700 and less than $750
per month.
A recent study reported that 22% of adults in France admitted to texting or e-mailing
while driving. A random sample of 110 French adults was randomly selected. What is
the probability that 26 or more of these adults admitted to admitted to texting or
e-mailing while driving?
A) 0.2218
B) 0.3409
C) 0.4030
D) 0.5748
The following data represents the amount of money that individuals spent on gifts for
Mother’s Day.
$110 $132 $144 $168 $141 $100 $184 $137 $134 $148 $128 $166
Construct a box-and-whisker plot for this data.
According to the National Health Interview Survey, 4.7% of U.S. adults 50 and older
have had a total knee replacement. A random sample of 20 adults 50 and older has been
selected. Use the Poisson distribution to approximate the binomial distribution to
determine the probability that no adults from this sample have had a total knee
replacement.
A) 0.1004
B) 0.1726
C) 0.2365
D) 0.3906
When you rely on the mean to summarize many data values, you lose important
information about the original data.
Consider the partially completed two-way ANOVA summary table.
The number of replications for this ANOVA procedure is _____.
A) 2
B) 3
C) 4
D) 5
Suppose the annual out-of-pocket health care expenses for retirees have a mean of
$10,700 and a standard deviation of $2,500. The percentage of retirees with annual
out-of-pocket health care costs between $5,700 and $15,700 is
A) approximately 68.
B) at least 89.
C) approximately 95.
D) at least 75.
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 mean square error for this model is ________.
A) 1,296,648,554
B) 12,236,421,969
C) 14,263,134,094
D) 36,709,265,906
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, and using α = 0.01, the conclusion for
this hypothesis test would be that because the test statistic is
___________________________________________________________________.
A) less than the critical value, the CDC cannot conclude that the proportion of obese
adults in the U.S. has increased this year when compared to last year
B) less than the critical value, the CDC can conclude that the proportion of obese adults
in the U.S. has increased this year when compared to last year
C) more than the critical value, the CDC cannot conclude that the proportion of obese
adults in the U.S. has increased this year when compared to last year
D) more than the critical value, the CDC can conclude that the proportion of obese
adults in the U.S. has increased this year when compared to last year
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.
The degrees of freedom for the critical value for Population 1 would be ________.
A) 24
B) 25
C) 27
D) 28
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 test statistic for testing the significance of the Exp variable is ________.
A) 1.91
B) 2.33
C) 2.51
D) 2.60
Use the information below to answer the following question(s).
Cars.com would like to use simple regression to predict the selling price of a used car,
in thousands of dollars, based on the age of the car in years. A random sample of used
cars was selected and the result of the regression analysis is shown below.
Which one of the following statements is true using α = 0.05?
A) Because the 95% confidence interval for the population slope includes zero, we can
reject the null hypothesis and conclude that there is a relationship between the age and
selling price of a used car.
B) Because the 95% confidence interval for the population slope includes zero, we fail
to reject the null hypothesis and conclude that there is a relationship between the age
and selling price of a used car.
C) Because the 95% confidence interval for the population slope does not include zero,
we fail to reject the null hypothesis and conclude that there is a relationship between the
age and selling price of a used car.
D) Because the 95% confidence interval for the population slope does not include zero,
we can reject the null hypothesis and conclude that there is a relationship between the
age and selling price of a used car.