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?