Question 1

If we reject a null hypothesis at the 1% significance level,then we have _________ evidence that the null hypothesis is false.

Accepted Answer

The answer of If we reject a null hypothesis at...

Question 2

A university interested in tracking its honors program believes that the proportion of graduates with a GPA of 3.00 or below is less than 0.20.In a sample of 200 graduates,30 students have a GPA of 3.00 or below.At a 5% significance level,the decision is to _________________________________________________________________________..

Accepted Answer

A)  reject Ho;we can conclude that the proportion of graduates with a GPA of 3.00 or below is significantly less than 0.20 
B)  reject Ho;we cannot conclude that the proportion of graduates with a GPA of 3.00 or below is significantly less than 0.20 
C)  not reject Ho;we can conclude that the proportion of graduates with a GPA of 3.00 or below is significantly less than 0.20 
D)  not reject Ho;we cannot conclude that the proportion of graduates with a GPA of 3.00 or below is significantly less than 0.20 
A)  reject Ho;we can conclude that the proportion of graduates with a GPA of 3.00 or below is significantly less than 0.20 
B)  reject Ho;we cannot conclude that the proportion of graduates with a GPA of 3.00 or below is significantly less than 0.20 
C)  not reject Ho;we can conclude that the proportion of graduates with a GPA of 3.00 or below is significantly less than 0.20 
D)  not reject Ho;we cannot conclude that the proportion of graduates with a GPA of 3.00 or below is significantly less than 0.20

Question 3

When conducting a hypothesis test for a given sample size,if a is increased from 0.05 to 0.10,then __________________.

Accepted Answer

A)  the probability of incorrectly rejecting the null hypothesis increases 
B)  the probability of incorrectly failing to reject the null hypothesis decreases 
C)  the probability of Type II error decreases 
D)  All of the above 
A)  the probability of incorrectly rejecting the null hypothesis increases 
B)  the probability of incorrectly failing to reject the null hypothesis decreases 
C)  the probability of Type II error decreases 
D)  All of the above

Question 4

A 99% confidence interval for the population mean yields the following results: [−3.79,5.86].At the 1% significance level,what decision should be made regarding the following hypothesis test with Ho:μ = 0,HA:μ ≠ 0?

Accepted Answer

A)  Reject Ho;we can conclude that the mean differs from zero. 
B)  Reject Ho;we cannot conclude that the mean differs from zero. 
C)  Do not reject Ho;we can conclude that the mean differs from zero. 
D)  Do not reject Ho;we cannot conclude that the mean differs from zero. 
A)  Reject Ho;we can conclude that the mean differs from zero. 
B)  Reject Ho;we cannot conclude that the mean differs from zero. 
C)  Do not reject Ho;we can conclude that the mean differs from zero. 
D)  Do not reject Ho;we cannot conclude that the mean differs from zero.

Question 5

A company decided to test the hypothesis that the average time a company's employees are spending to check their private e-mails at work is more than 6 minutes.A random sample of 40 employees were selected and they averaged 6.6 minutes.It is believed that the population standard deviation is 1.7 minutes.The α is set to 0.05.The critical value for this hypothesis test would be ______.

Accepted Answer

A)  6.0 
B)  7.4 
C)  6.4 
D)  7.9 
A)  6.0 
B)  7.4 
C)  6.4 
D)  7.9

Question 6

Students who graduated from college in 2010 with student loans owed an average of $25,250 (TheNew York Times,November 2,2011).An economist wants to determine if the average debt has increased since 2010.She takes a sample of 40 recent graduates and finds that their average debt was $28,275.Assume that the population standard deviation is $7,250.
a.Specify the competing hypotheses to determine whether the average undergraduate debt has increased since 2001.
b.Calculate the value of the test statistic and the p-value.
c.At the 5% significance level,can you conclude that the average undergraduate debt has increased? Explain.

Accepted Answer

To establish whether the mean exceeds so

Question 7

Expedia would like to test if the average round-trip airfare between Philadelphia and Dublin is less than $1,200.Which of the following hypothesis tests should be performed?

Accepted Answer

A)  Left-tailed 
B)  Right-tailed 
C)  Two-tailed 
D)  There is not enough information to answer. 
A)  Left-tailed 
B)  Right-tailed 
C)  Two-tailed 
D)  There is not enough information to answer.

Question 8

The Institute of Education Sciences measures the high school dropout rate as the percentage of 16-through 24-year-olds who are not enrolled in school and have not earned a high school credential.In 2009,the high school dropout rate was 8.1%.A polling company recently took a survey of 1,000 people between the ages of 16 and 24 and found that 6.5% of them are high school dropouts.The polling company would like to determine whether the dropout rate has decreased.When testing whether the dropout rate has decreased,the appropriate hypotheses are _____________.

Accepted Answer

A)    
B)    
C)    
D)    
A)    
B)    
C)    
D)

Question 9

Many cities around the United States are installing LED streetlights,in part to combat crime by improving visibility after dusk.An urban police department claims that the proportion of crimes committed after dusk will fall below the current level of 0.84 if LED streetlights are installed.Specify the null and alternative hypotheses to test the police department's claim.

Accepted Answer

A) H0:p = 0.84 and HA:p ≠ 0.84 B) H0:p A:p ≥ 0.84 C) H0:p ≤ 0.84 and HA:p > 0.84 D) H0:p ≥ 0.84 and HA:p < 0.84 A) H0:p = 0.84 and HA:p ≠ 0.84 B) H0:p A:p ≥ 0.84 C) H0:p ≤ 0.84 and HA:p > 0.84 D) H0:p ≥ 0.84 and HA:p < 0.84

Question 10

The Institute of Education Sciences measures the high school dropout rate as the percentage of 16- through 24-year-olds who are not enrolled in school and have not earned a high school credential.In 2009,the high school dropout rate was 8.1%.A polling company recently took a survey of 1,000 people between the ages of 16 and 24 and found that 6.5% of them are high school dropouts.The polling company would like to determine whether the dropout rate has decreased.The value of the test statistic is ____________.

Accepted Answer

A)  z = -2.052 
B)  z = -1.854 
C)  z = 1.854 
D)  z = 2.052 
A)  z = -2.052 
B)  z = -1.854 
C)  z = 1.854 
D)  z = 2.052

Question 11

A hairdresser believes that she is more profitable on Tuesdays,her lucky day of the week.She knows that,on average,she has a daily revenue of $250.She randomly samples the revenue from eight Tuesdays and finds she takes in $260,$245,$270,$260,$295,$235,$270,and $265.Assume that daily revenue is normally distributed.
a.Specify the population parameter to be tested.
b.Specify the null and alternative hypotheses to test the hairdresser's claim.
c.Calculate the sample mean revenue and the sample standard deviation.
d.Compute the value of the appropriate test statistic.
e.At the 10% significance level,specify the critical value(s).
f.At the 10% significance level,is the hairdresser's claim supported by the data?

Accepted Answer

The competing hypotheses are H_o:μ ≤ μ_o,H_A:μ

Question 12

The Institute of Education Sciences measures the high school dropout rate as the percentage of 16- through 24-year-olds who are not enrolled in school and have not earned a high school credential.In 2009,the high school dropout rate was 8.1%.A polling company recently took a survey of 1,000 people between the ages of 16 and 24 and found that 6.5% of them are high school dropouts.The polling company would like to determine whether the dropout rate has decreased.At a 5% significance level,the p-value and α are _____________________.

Accepted Answer

A)  p-value = 0.0210 and α = 0.05 
B)  p-value = 0.0319 and α = 0.05 
C)  p-value = 0.0210 and α = 0.025 
D)  p-value = 0.0319 and α = 0.025 
A)  p-value = 0.0210 and α = 0.05 
B)  p-value = 0.0319 and α = 0.05 
C)  p-value = 0.0210 and α = 0.025 
D)  p-value = 0.0319 and α = 0.025

Question 13

In a one-tailed test,the rejection region is located under one tail (left or right)of the corresponding probability distribution,while in a two-tailed test this region is located under both tails.

Accepted Answer

A) True 
 B)False

Question 14

The alternative hypothesis typically ___________.

Accepted Answer

A)  corresponds to the presumed default state of nature 
B)  contests the status quo,for which a corrective action may be required 
C)  states the probability of rejecting the null hypothesis when it is false 
D)  states the probability of rejecting the null hypothesis when it is true 
A)  corresponds to the presumed default state of nature 
B)  contests the status quo,for which a corrective action may be required 
C)  states the probability of rejecting the null hypothesis when it is false 
D)  states the probability of rejecting the null hypothesis when it is true

Question 15

It is generally believed that no more than 0.50 of all babies in a town in Texas are born out of wedlock.A politician claims that the proportion of babies born out of wedlock is increasing.In testing the politician's claim,how does one define the population parameter of interest?

Accepted Answer

A)  The current proportion of babies born out of wedlock 
B)  The mean number of babies born out of wedlock 
C)  The number of babies born out of wedlock 
D)  The general belief that the proportion of babies born out of wedlock is no more than 0.50 
A)  The current proportion of babies born out of wedlock 
B)  The mean number of babies born out of wedlock 
C)  The number of babies born out of wedlock 
D)  The general belief that the proportion of babies born out of wedlock is no more than 0.50

Question 16

Expedia would like to test if the average round-trip airfare between Philadelphia and Dublin is less than $1,200.The correct hypothesis statement would be __________________________.

Accepted Answer

A)    
B)    
C)    
D)    
A)    
B)    
C)    
D)

Question 17

The Boston public school district has had difficulty maintaining on-time bus service for its students ("A Year Later,School Buses Still Late," Boston Globe,October 5,2011).Suppose the district develops a new bus schedule to help combat chronic lateness on a particularly woeful route.Historically,the bus service on the route has been,on average,12 minutes late.After the schedule adjustment,the first 36 runs were an average of eight minutes late.As a result,the Boston public school district claimed that the schedule adjustment was an improvement-students were not as late.Assume a population standard deviation for bus arrival time of 12 minutes.The value of the test statistic is ____________.

Accepted Answer

A)  t35 = -2.00 
B)  z = -2.00 
C)  t35 = -0.33 
D)  z = -0.33 
A)  t35 = -2.00 
B)  z = -2.00 
C)  t35 = -0.33 
D)  z = -0.33

Question 18

The owner of a large car dealership believes that the financial crisis decreased the number of customers visiting her dealership.The dealership has historically had 800 customers per day.The owner takes a sample of 100 days and finds the average number of customers visiting the dealership per day was 750.Assume that the population standard deviation is 350.The population parameter to be tested is ___________.

Accepted Answer

A)  the average number of 750 customers per day 
B)  the proportion of customers visiting the dealership per day 
C)  the mean number of customers visiting the dealership per day 
D)  the standard deviation of the number of customers visiting the dealership per day 
A)  the average number of 750 customers per day 
B)  the proportion of customers visiting the dealership per day 
C)  the mean number of customers visiting the dealership per day 
D)  the standard deviation of the number of customers visiting the dealership per day

Question 19

When conducting a hypothesis test,which of the following decisions represents an error?

Accepted Answer

A)  Rejecting the null hypothesis when it is true. 
B)  Rejecting the null hypothesis when it is false. 
C)  Not rejecting the null hypothesis when it is true. 
D)  Rejecting the null hypothesis when it is false and not rejecting the null hypothesis when it is true. 
A)  Rejecting the null hypothesis when it is true. 
B)  Rejecting the null hypothesis when it is false. 
C)  Not rejecting the null hypothesis when it is true. 
D)  Rejecting the null hypothesis when it is false and not rejecting the null hypothesis when it is true.

Question 20

It is generally believed that no more than 0.50 of all babies in a town in Texas are born out of wedlock.A politician claims that the proportion of babies born out of wedlock is increasing.When testing the two hypotheses,H0: p ≤ 0.50 and HA: p > 0.50,p stands for _____________.

Accepted Answer

A)  the current proportion of babies born out of wedlock 
B)  the mean number of babies born out of wedlock 
C)  the number of babies born out of wedlock 
D)  the general belief that the proportion of babies born out of wedlock is no more than 0.50 
A)  the current proportion of babies born out of wedlock 
B)  the mean number of babies born out of wedlock 
C)  the number of babies born out of wedlock 
D)  the general belief that the proportion of babies born out of wedlock is no more than 0.50

If we reject a null hypothesis at the 1% significance level,then we have _________ evidence that the null hypothesis is false.

When conducting a hypothesis test for a given sample size,if a is increased from 0.05 to 0.10,then __________________.

A 99% confidence interval for the population mean yields the following results: [−3.79,5.86].At the 1% significance level,what decision should be made regarding the following hypothesis test with H_o:μ = 0,H_A:μ ≠ 0?

Expedia would like to test if the average round-trip airfare between Philadelphia and Dublin is less than $1,200.Which of the following hypothesis tests should be performed?

In a one-tailed test,the rejection region is located under one tail (left or right)of the corresponding probability distribution,while in a two-tailed test this region is located under both tails.

The alternative hypothesis typically ___________.

It is generally believed that no more than 0.50 of all babies in a town in Texas are born out of wedlock.A politician claims that the proportion of babies born out of wedlock is increasing.In testing the politician's claim,how does one define the population parameter of interest?

Expedia would like to test if the average round-trip airfare between Philadelphia and Dublin is less than $1,200.The correct hypothesis statement would be __________________________.

When conducting a hypothesis test,which of the following decisions represents an error?

It is generally believed that no more than 0.50 of all babies in a town in Texas are born out of wedlock.A politician claims that the proportion of babies born out of wedlock is increasing.When testing the two hypotheses,H₀: p ≤ 0.50 and H_A: p > 0.50,p stands for _____________.

Statistics and Data

Tabular and Graphical Methods

Numerical Descriptive Measures

Basic Probability Concepts

Discrete Probability Distributions

Continuous Probability Distributions

Sampling and Sampling Distributions

Interval Estimation

Statistical Inference Concerning Two Populations

Statistical Inference Concerning Variance

Chi-Square Tests

Analysis of Variance

Regression Analysis

Inference With Regression Models

Regression Models for Nonlinear Relationships

Regression Models With Dummy Variables

Time Series and Forecasting

Returns, Index Numbers and Inflation

Nonparametric Tests

Filters

Exam 9: Hypothesis Testing

If we reject a null hypothesis at the 1% significance level,then we have _________ evidence that the null hypothesis is false.

When conducting a hypothesis test for a given sample size,if a is increased from 0.05 to 0.10,then __________________.

A 99% confidence interval for the population mean yields the following results: [−3.79,5.86].At the 1% significance level,what decision should be made regarding the following hypothesis test with Ho:μ = 0,HA:μ ≠ 0?

Expedia would like to test if the average round-trip airfare between Philadelphia and Dublin is less than $1,200.Which of the following hypothesis tests should be performed?

In a one-tailed test,the rejection region is located under one tail (left or right)of the corresponding probability distribution,while in a two-tailed test this region is located under both tails.

The alternative hypothesis typically ___________.

It is generally believed that no more than 0.50 of all babies in a town in Texas are born out of wedlock.A politician claims that the proportion of babies born out of wedlock is increasing.In testing the politician's claim,how does one define the population parameter of interest?

Expedia would like to test if the average round-trip airfare between Philadelphia and Dublin is less than $1,200.The correct hypothesis statement would be __________________________.

When conducting a hypothesis test,which of the following decisions represents an error?

It is generally believed that no more than 0.50 of all babies in a town in Texas are born out of wedlock.A politician claims that the proportion of babies born out of wedlock is increasing.When testing the two hypotheses,H0: p ≤ 0.50 and HA: p > 0.50,p stands for _____________.

Statistics and Data

Tabular and Graphical Methods

Numerical Descriptive Measures

Basic Probability Concepts

Discrete Probability Distributions

Continuous Probability Distributions

Sampling and Sampling Distributions

Interval Estimation

Statistical Inference Concerning Two Populations

Statistical Inference Concerning Variance

Chi-Square Tests

Analysis of Variance

Regression Analysis

Inference With Regression Models

Regression Models for Nonlinear Relationships

Regression Models With Dummy Variables

Time Series and Forecasting

Returns, Index Numbers and Inflation

Nonparametric Tests

Filters

A 99% confidence interval for the population mean yields the following results: [−3.79,5.86].At the 1% significance level,what decision should be made regarding the following hypothesis test with H_o:μ = 0,H_A:μ ≠ 0?

It is generally believed that no more than 0.50 of all babies in a town in Texas are born out of wedlock.A politician claims that the proportion of babies born out of wedlock is increasing.When testing the two hypotheses,H₀: p ≤ 0.50 and H_A: p > 0.50,p stands for _____________.