Question 11 pts
The mathematical science that deals with the collection, analysis, and
presentation of data is
Mathematical analysis
Statistics
Economics
Data
analysis
Question 21 pts
Sampling error is the difference between the __________ and the parameter.
Statistic
Sample
Sample mode
None of the above
Question 31 pts
The __________ is the probability distribution used in place of the normal
distribution to calculate a confidence interval when the population standard
deviation is unknown.
Exponential
distribution
Uniform distribution
Student’s t
distribution
Binomial distribution
Question 41 pts
A __________ is a distribution in which the probability of any interval occurring is
equal to any other interval with the same width.
Student’s t
distribution
Binomial distribution
Uniform distribution
Normal distribution
Question 51 pts
The number of rushing touchdowns for the Minnesota Vikings in a season is an
example of
Ordinal data
Interval
data
Ratio data
Nominal data
Question 6
Which is a continuous random variable?
The number of students in an ECO 250 class.
The number of births in a hospital on a given
day.
The number of fives obtained in four rolls of a die.
The hourly earnings of a call center employee in
Boston.
Question 7
The empirical rule states if a distribution is symmetrical and bell-shaped,
approximately 68%, 95%, and _______ of its data values will fall within one, two,
and three standard deviations above and below the mean, respectively.
99.7%
98%
99%
99.5%
Question 8
__________ is the probability that the interval estimate will include the population
parameter of interest, such as a mean.
Confidence level
Degrees of freedom
Significance
level
Margin of error
Question 9
The __________ is a variable that represents the probability that any given
confidence interval will not contain the true population mean.
Significance
level
Confidence level
Degrees of freedom
Margin of error
Question 10
What is an error that occurs when the null hypothesis is rejected when, in reality,
it is true?
None of the above
Type II error
Sampling error
Type I error
Question 11
Which is a time series variable?
VISA balances of 30 students on December 31 of this year.
Titles of the top 10 movies in total revenue last week
Net earnings reported by Xena Corp for the last 10 quarters.
Dollar exchange rates yesterday against 10 other world
currencies
Question 12
A tire company performs quality-control tests on the monthly output of its bestselling model tire at each of its plants. Each month a random sample of 25 tires is
selected from each plant and tested to see if the average tread life of that plant’s
tires is above specifications. For one plant, the random sample of 25 tires had a
sample mean of 39,500 miles and a sample standard deviation of 3,300 miles.
The company performs a hypothesis test at the .05 level of significance to see if
there is evidence that the average tread life is greater than 38,000. Based on this
sample, the company should:
Fail to reject the null hypothesis and conclude there is evidence that the average tread life is greater than
38,000 miles
Reject the null hypothesis and conclude there is not evidence that the average tread life is greater than
38,000 miles.
Fail to reject the null hypothesis and conclude there is not evidence that the average tread life is greater
than 38,000 miles.
Reject the null hypothesis and conclude there is evidence that the average tread life is greater than 38,000
miles.
Question 13
What is the probability of observing a sample mean at least as extreme as the
one selected for the hypothesis test, assuming the null hypothesis is true?
pvalue
Alpha
Confidence
level
Beta
Question 14
Which is not a characteristic of a binomial experiment?
Each trial has only two possible outcomes: a success or a
failure
Each trial is independent of the other trials in the experiment
The experiment consists of an infinite number of trials.
The probability of success is equal to one minus the probability of
failure
Question 15
A __________ is a continuous distribution that is bell shaped and symmetrical
around the mean.
Binomial distribution
Exponential
distribution
Uniform distribution
Normal distribution
Question 16
The critical z-score for an 85% confidence level is ________.
2.33
1.44
1.28
1.96
Question 17
YouTube would like to test the hypothesis that the average length of an online
video watched by a user is more than 6 minutes. A random sample of 40 people
watched online videos that averaged 6.6 minutes in length. The population
standard deviation for the length of online videos is 1.7 minutes. YouTube would
like to set
_________.
0.0268
0.0129
0.0395
0.0644
α=0.05. The p-value for this hypothesis test would be
Question 18
A professor would like to test the hypothesis that the average number of minutes
that a student needs to complete a statistics exam is equal to 45 minutes. The
correct hypothesis statement would be
Question 19
What should you do when the p-value is less than the significance level?
Accept the alternative
hypothesis
Accept the null hypothesis
Fail to reject the null
hypothesis
Reject the null hypothesis
Question 20
Consider the following set of numbers: 10, 25, 13, 18, 40, 5. Determine the
median and variance of these data.
median = 18.5, variance =
12.57
median = 15.5, variance =
157.9
median = 15.5, variance = 35
median = 18.5, variance = 473.83
Question 21
A point estimate, also called a statistic, is a single value that describes the
population of interest, with the sample mean being the most common.
True
False
Question 22
The margin of error is the width of the confidence interval between the lower
limit and the upper limit.
True
False
Question 23
The alternative hypothesis represents the status quo and involves stating the
belief that the population parameter is
always associated with the equal sign.
a specific value and is
True
False
Question 24
A z-score measures the number of standard deviations a value is from its mode.
True
False
Question 25
Suppose Nike’s average stock price this year is $15.00 with a standard deviation
of $3.00, and Under Armour’s average stock price this year is $24.00 with a
standard deviation of $4.00. According to this data, Nike’s stock price is more
consistent than Under Armour’s stock price.
True
False
Question 26
The Central Limit Theorem states that sample means, drawn from a normally
distributed population, will be normally distributed.
True
False
Question 27
A low p-value indicates a high probability that the null hypothesis is not true.
True
False
Question 28
If the absolute value of the test statistic is less than the critical value in a twotailed hypothesis test, then the decision is to reject the null hypothesis.
True
False
Question 29
Consider the hypotheses
H0: Defendant is innocent
H1: Defendant is guilty
If a court acquits every defendant, they will never commit Type II error.
True
False
Question 30
If we do not have evidence to support the alternative hypothesis, then we accept
the null hypothesis.
True
False
Question 31
Suppose the average puppy weighs 10 pounds. A sample of 10 puppies yields a
sample mean of 13.2 pounds and a sample standard deviation of 2.78
pounds. Assume the population standard deviation is known to be 5.25.You want
to test whether the sample mean differs from the population mean of 10 pounds
at a 5 percent level of significance using a two-tailed test. What are your null and
alternative hypotheses?
Question 32
Suppose the average puppy weighs 10 pounds. A sample of 10 puppies yields a
sample mean of 13.2 pounds and a sample standard deviation of 2.78
pounds. Assume the population standard deviation is known to be 5.25.You want
to test whether the sample mean differs from the population mean of 10 pounds
at a 5 percent level of significance using a two-tailed test. Calculate the test
statistic for the sample data.
Question 33
Suppose the average puppy weighs 10 pounds. A sample of 10 puppies yields a
sample mean of 13.2 pounds and a sample standard deviation of 2.78
pounds. Assume the population standard deviation is known to be 5.25.You want
to test whether the sample mean differs from the population mean of 10 pounds
at a 5 percent level of significance using a two-tailed test. State the critical value.
Question 34
Suppose the average puppy weighs 10 pounds. A sample of 10 puppies yields a
sample mean of 13.2 pounds and a sample standard deviation of 2.78
pounds. Assume the population standard deviation is known to be 5.25.You want
to test whether the sample mean differs from the population mean of 10 pounds
at a 5 percent level of significance using a two-tailed test. Determine whether or
not the null hypothesis should be rejected.
Fail to reject the null
hypothesis.
Reject the null hypothesis.
Question 35
Consider the following data on the number of beers consumed by a sample of
football fans during a game:
3 5 0 2 5 3.
Calculate the mean number of beers.
Question 36
Consider the following data on the number of beers consumed by a sample of
football fans during a game:
3 5 0 2 5 3.
Calculate the median.
Question 37
Consider the following data on the number of beers consumed by a sample of
football fans during a game:
3 5 0 2 5 3.
Calculate the mode (mark all that apply).
0
3
2
5
Question 38
Consider the following data on the number of beers consumed by a sample of
football fans during a game:
3 5 0 2 5 3.
Calculate the variance.
Question 39
You check the weather forecast every morning. On average, it is rainy 20 percent
of the time. Consider the next 5 days. What is the probability it will be rainy
exactly 1 day?
Question 40
You check the weather forecast every morning. On average, it is rainy 20 percent
of the time. Consider the next 5 days. What is the probability it will be rainy at
most 2 days?
Question 41
The average batter life of the iPhone 4S is reported to be 6.0 hours by Apple.
Assume that the population standard deviation for the better life for this cell
phone is 30 minutes. A random sample of 50 iPhones had an average better life
of 5.7 hours. Determine the margin of error (in hours) for the 90% confidence
interval for this sample.
Question 42
The average batter life of the iPhone 4S is reported to be 6.0 hours by Apple.
Assume that the population standard deviation for the better life for this cell
phone is 30 minutes. A random sample of 50 iPhones had an average better life
of 5.7 hours. Determine the lower confidence limit (LCL), in hours, for the 90%
confidence interval for this sample.
Question 43
The average batter life of the iPhone 4S is reported to be 6.0 hours by Apple.
Assume that the population standard deviation for the better life for this cell
phone is 30 minutes. A random sample of 50 iPhones had an average better life
of 5.7 hours. Determine the upper confidence limit (UCL), in hours, for the 90%
confidence interval for this sample.
Question 44
Consider the following discrete probability distribution.
X P(X)
0
0.2
1
0.3
2
0.4
3
0.1
Total
1.0
Calculate the mean of this distribution.
Question 45
Consider the following discrete probability distribution.
X P(X)
0
0.2
1
2
0.3
0.4
3
Total
0.1
1.0
Calculate the variance of this distribution.
Question 46
The commute time to work for a particular employee follows a continuous
uniform distribution with a minimum time of 9 minutes and a maximum time of
25 minutes.
What is the mean of this distribution?
Question 47
The commute time to work for a particular employee follows a continuous
uniform distribution with a minimum time of 9 minutes and a maximum time of
25 minutes.
What is the probability that the employee’s next commute to work will require
less than 10 minutes?
Question 48
The commute time to work for a particular employee follows a continuous
uniform distribution with a minimum time of 9 minutes and a maximum time of
25 minutes.
What is the probability that the employee’s next commute time will require
between 12 minutes and 20 minutes?
Question 49
Consider the following hypothesis:
H1:μ>25
Given that
test statistic.
calculate the
Question 50
Consider the following hypothesis:
H1:μ>25
Given that
state the
critical value.
Question 51
Consider the following hypothesis:
H1:μ>25
Given that
whether or not the null hypothesis should be rejected.
determine
Reject the null hypothesis
Fail to reject the null
hypothesis
Question 52
A tire manufacturer selected a random sample of 50 tires of a particular model
chosen from the past month’s production and used destructive testing to
determine the tread life of each tire. The sample mean was 42,300 miles and the
sample standard deviation was 7,500 miles. What is the 95% confidence interval
estimate for the tread life of that entire model produced in the past month?
Question 53
Suppose the average number of complaints received by Christiana Hospital from
patients is 7.4 every four weeks. Assume the number of complaints per month
follows the Poisson distribution.
What is the probability of exactly four complaints during the next four weeks?
Question 54
Suppose the average number of complaints received by Christiana Hospital from
patients is 7.4 every four weeks. Assume the number of complaints per month
follows the Poisson distribution.
What is the probability of four or more complaints during the next four weeks?
Question 55
Suppose the average number of complaints received by Christiana Hospital from
patients is 7.4 every four weeks. Assume the number of complaints per month
follows the Poisson distribution.
What is the probability of exactly three complaints during the next two weeks?
Question 56
Zombies eat, on average, 5 brains per day. Assume the actual number of brains
eaten per day follows the normal distribution with a standard deviation of 0.29
brains. What is the probability that a zombie will eat exactly 3.2 brains tomorrow?
