Question 1

If α = 0.05 for a two-tailed test, how large is the acceptance area?

Accepted Answer

A)  0.050 
B)  0.025 
C)  0.950 
D)  0.975 
A)  0.050 
B)  0.025 
C)  0.950 
D)  0.975

Question 2

The mean length of a candy bar is 43 millimeters. There is concern that the settings of the machine
Cutting the bars have changed. Test the claim at the 0.02 level that there has been no change in the
Mean length. The alternate hypothesis is that there has been a change. Twelve bars (n = 12) were
Selected at random and their lengths recorded. The lengths are (in millimeters) 42, 39, 42, 45, 43,
40, 39, 41, 40, 42, 43, and 42. Has there been a statistically signiﬁcant change in the mean length of
The bars?

Accepted Answer

A)  Yes, because the computed t lies in the rejection region. 
B)  No, because the information given is not complete. 
C)  No, because the computed t lies in the area to the right of -2.718. 
D)  Yes, because 43 is greater than 41.5. 
A)  Yes, because the computed t lies in the rejection region. 
B)  No, because the information given is not complete. 
C)  No, because the computed t lies in the area to the right of -2.718. 
D)  Yes, because 43 is greater than 41.5.

Question 3

Based on the Nielsen ratings, the local CBS aﬃliate claims its 11 p.m. newscast reaches 41% of the
Viewing audience in the area. In a survey of 81 viewers, 36% indicated that they watch the late
Evening news on this local CBS station. What is the z test statistic?

Accepted Answer

A)  1.02 
B)  1.22 
C)  -.91 
D)  -1.22 
A)  1.02 
B)  1.22 
C)  -.91 
D)  -1.22

Question 4

Based on the Nielsen ratings, the local CBS aﬃliate claims its 11:00 PM newscast reaches 41% of the
Viewing audience in the area. In a survey of 100 viewers, 36% indicated that they watch the late
Evening news on this local CBS station.
What is the null hypothesis?

Accepted Answer

A)  p = 0.36 
B)  p = 0.41 
C)  p ≠ 0.36 
D)  μ = 0.41 
A)  p = 0.36 
B)  p = 0.41 
C)  p ≠ 0.36 
D)  μ = 0.41

Question 5

i. The level of signiﬁcance is the risk we assume of rejecting the null hypothesis when it is actually
True.
ii. There is only one level of signiﬁcance that is applied to all studies involving sampling.
iii. The researcher must decide on the level of signiﬁcance before formulating a decision rule and
Collecting sample data.

Accepted Answer

A)  (i), (ii), and (iii) are all correct statements. 
B)  (i) is a correct statement but not (ii) or (iii). 
C)  (i) and (iii) are correct statements but not (ii). 
D)  (i) and (ii) are correct statements but not (iii). 
E)  (i), (ii), and (iii) are all false statements. 
A)  (i), (ii), and (iii) are all correct statements. 
B)  (i) is a correct statement but not (ii) or (iii). 
C)  (i) and (iii) are correct statements but not (ii). 
D)  (i) and (ii) are correct statements but not (iii). 
E)  (i), (ii), and (iii) are all false statements.

Question 6

What is the critical z-value for a one-tailed lower test at the 1% level of risk?

Accepted Answer

A)  +2.58 
B)  -2.58 
C)  +2.33 
D)  -2.33 
A)  +2.58 
B)  -2.58 
C)  +2.33 
D)  -2.33

Question 7

A restaurant that bills its house account monthly is concerned that the average monthly bill exceeds
$200 per account. A random sample of twelve accounts is selected, resulting in a sample mean of
$220 and a standard deviation of $12. The t-test is to be conducted at the 5% level of signiﬁcance.

Accepted Answer

A)  The critical value of t is +1.796. The calculated value of t is +5.77. 
B)  The critical value of t is -1.796. The calculated value of t is -5.77. 
C)  The critical value of t is +2.201. The calculated value of t is +5.77. 
D)  The critical value of t is +2.201. The calculated value of t is +1.40. 
E)  The critical value of t is +2.201. The calculated value of t is -5.77. 
A)  The critical value of t is +1.796. The calculated value of t is +5.77. 
B)  The critical value of t is -1.796. The calculated value of t is -5.77. 
C)  The critical value of t is +2.201. The calculated value of t is +5.77. 
D)  The critical value of t is +2.201. The calculated value of t is +1.40. 
E)  The critical value of t is +2.201. The calculated value of t is -5.77.

Question 8

Given: null hypothesis is that the population mean is 16.9 against the alternative hypothesis that the
Population mean is not equal to 16.9. A random sample of 25 items results in a sample mean of 18.0
And the sample standard deviation is 2.4. It can be assumed that the population is normally
Distributed. Determine the observed "t" value.

Accepted Answer

A)  t = 2.29 
B)  t = 1.83 
C)  t = 1.75 
D)  t = 2.01 
A)  t = 2.29 
B)  t = 1.83 
C)  t = 1.75 
D)  t = 2.01

Question 9

i. The ﬁfth and ﬁnal step in testing a hypothesis is taking a sample and, based on the decision rule,
Deciding if the null hypothesis should be rejected.
ii. When the null hypothesis is not rejected, the conclusion is that our sample data does not allow us
To reject the null hypothesis.
iii. The level of signiﬁcance is selected after setting up a decision rule and sampling the population.

Accepted Answer

A)  (i), (ii), and (iii) are all correct statements. 
B)  (i) is a correct statement but not (ii) or (iii). 
C)  (i) and (iii) are correct statements but not (ii). 
D)  (i) and (ii) are correct statements but not (iii). 
E)  (i), (ii), and (iii) are all false statements. 
A)  (i), (ii), and (iii) are all correct statements. 
B)  (i) is a correct statement but not (ii) or (iii). 
C)  (i) and (iii) are correct statements but not (ii). 
D)  (i) and (ii) are correct statements but not (iii). 
E)  (i), (ii), and (iii) are all false statements.

Question 10

The average cost of tuition, room and board at community colleges is reported to be $11,500 per
Year, but a ﬁnancial administrator believes that the average cost is higher. A study conducted using
150 community colleges showed that the average cost per year is $12,000 with a standard
Deviation of $1,200. Let α = 0.05.
What are the null and alternative hypotheses for this study?

Accepted Answer

A) Null: μ ≤ $12,000; alternative: μ > $12,000 B) Null: μ ≤ $12,000; alternative: μ $11,500 D) Null: μ ≤ $11,500; alternative: μ < $11,500 A) Null: μ ≤ $12,000; alternative: μ > $12,000 B) Null: μ ≤ $12,000; alternative: μ $11,500 D) Null: μ ≤ $11,500; alternative: μ < $11,500

Question 11

i. Two types of possible errors always exist when testing hypotheses-a Type I error, in which the
Null hypothesis is rejected when it should not have been rejected, and a Type II error in which the
Null hypothesis is not rejected when it should have been rejected.
ii. A test statistic is a value determined from sample information collected to test the null hypothesis.
iii. The region or area of rejection deﬁnes the location of all those values that are so large or so
Small that the probability of their occurrence under a true null hypothesis is rather remote.

Accepted Answer

A)  (i), (ii), and (iii) are all correct statements. 
B)  (i) is a correct statement but not (ii) or (iii). 
C)  (i) and (iii) are correct statements but not (ii). 
D)  (i) and (ii) are correct statements but not (iii). 
E)  (i), (ii), and (iii) are all false statements. 
A)  (i), (ii), and (iii) are all correct statements. 
B)  (i) is a correct statement but not (ii) or (iii). 
C)  (i) and (iii) are correct statements but not (ii). 
D)  (i) and (ii) are correct statements but not (iii). 
E)  (i), (ii), and (iii) are all false statements.

Question 12

A manufacturer claims that less than 1% of all his products do not meet the minimum government
Standards. A survey of 500 products revealed ten did not meet the standard. If the z-statistic is
-2)58 and the level of signiﬁcance is 0.02, what is your decision?

Accepted Answer

A)  You reject the null hypothesis, and agree that less than 1% fail to meet government standards. 
B)  You have insuﬃcient evidence to reject the null hypothesis. 
C)  You reject the alternate hypothesis and agree that less than 1% meet government standards. 
D)  You should have used the t-test. 
A)  You reject the null hypothesis, and agree that less than 1% fail to meet government standards. 
B)  You have insuﬃcient evidence to reject the null hypothesis. 
C)  You reject the alternate hypothesis and agree that less than 1% meet government standards. 
D)  You should have used the t-test.

Question 13

A manufacturer claims that less than 1% of all his products do not meet the minimum government
Standards. A survey of 500 products revealed ten did not meet the standard.
If the z-statistic is -2.054 and the level of signiﬁcance is 0.03, what is your decision?

Accepted Answer

A)  You reject the null hypothesis, and agree that less than 1% fail to meet government standards. 
B)  You have insuﬃcient evidence to reject the null hypothesis. 
C)  You reject the alternate hypothesis and agree that less than 1% meet government standards. 
D)  You should have used the t-test. 
A)  You reject the null hypothesis, and agree that less than 1% fail to meet government standards. 
B)  You have insuﬃcient evidence to reject the null hypothesis. 
C)  You reject the alternate hypothesis and agree that less than 1% meet government standards. 
D)  You should have used the t-test.

Question 14

A restaurant that bills its house account monthly is concerned that the average monthly bill exceeds
$200 per account. A random sample of twelve accounts is selected, resulting in a sample mean of
$220 and a standard deviation of $12. The t-test is to be conducted at the 5% level of signiﬁcance.
Given the following printout, what can you determine?

Accepted Answer

A)  The alternate hypothesis is μ ≤ 200 
B)  You should accept the null hypothesis at the 0.05 level of signiﬁcance. 
C)  There is less than a 1% chance of getting these results if the null hypothesis is true, so you have very strong evidence to suggest that the average bill is more than $200. 
D)  There is less than a 1% chance of getting these results if the null hypothesis is true, so you have very strong evidence to suggest that the average bill is less than $200. 
E)  The alternate hypothesis is μ ≤ 200 and you should accept the null hypothesis at the 0.05 level of signiﬁcance. 
A)  The alternate hypothesis is μ ≤ 200 
B)  You should accept the null hypothesis at the 0.05 level of signiﬁcance. 
C)  There is less than a 1% chance of getting these results if the null hypothesis is true, so you have very strong evidence to suggest that the average bill is more than $200. 
D)  There is less than a 1% chance of getting these results if the null hypothesis is true, so you have very strong evidence to suggest that the average bill is less than $200. 
E)  The alternate hypothesis is μ ≤ 200 and you should accept the null hypothesis at the 0.05 level of signiﬁcance.

Question 15

A manufacturer wants to increase the shelf life of a line of cake mixes. Past records indicate that the
Average shelf life of the mix is 216 days. After a revised mix has been developed, a sample of nine
Boxes of cake mix gave these shelf lives (in days): 215, 217, 218, 219, 216, 217, 217, 218 and 218. At the
0)025 level, has the shelf life of the cake mix increased?

Accepted Answer

A)  Yes, because computed t is greater than the critical value. 
B)  Yes, because computed t is less than the critical value. 
C)  No, because computed t lies in the region of acceptance. 
D)  No, because 217.24 is quite close to 216. 
A)  Yes, because computed t is greater than the critical value. 
B)  Yes, because computed t is less than the critical value. 
C)  No, because computed t lies in the region of acceptance. 
D)  No, because 217.24 is quite close to 216.

Question 16

Given: null hypothesis is that the population mean is 16.9 against the alternative hypothesis that the
Population mean is not equal to 16.9. A random sample of 16 items results in a sample mean of 17.8
And the sample standard deviation is 2.4. It can be assumed that the population is normally
Distributed. Determine the observed "t" value.

Accepted Answer

A)  t = 2.12 
B)  t = 1.50 
C)  t = 1.75 
D)  t = 1.00 
A)  t = 2.12 
B)  t = 1.50 
C)  t = 1.75 
D)  t = 1.00

Question 17

What must both np and n(1 - p) exceed in testing a hypothesis involving one proportion?

Accepted Answer

A)  5 
B)  30 
C)  100 
D)  2,000 
A)  5 
B)  30 
C)  100 
D)  2,000

Question 18

The mean length of a candy bar is 43 millimeters. There is concern that the settings of the machine
Cutting the bars have changed. Test the claim at the 0.02 level that there has been no change in the
Mean length. The alternate hypothesis is that there has been a change. Twelve bars (n = 12) were
Selected at random and their lengths recorded. The lengths are (in millimeters) 42, 39, 42, 45, 43,
40, 39, 41, 40, 42, 43, and 42. The mean of the sample is 41.5 and the standard deviation is 1.784.
Computed t = -2.913. Has there been a statistically signiﬁcant change in the mean length of the
Bars?

Accepted Answer

A)  Yes, because the computed t lies in the rejection region. 
B)  No, because the information given is not complete. 
C)  No, because the computed t lies in the area to the right of -2.718. 
D)  Yes, because 43 is greater than 41.5. 
A)  Yes, because the computed t lies in the rejection region. 
B)  No, because the information given is not complete. 
C)  No, because the computed t lies in the area to the right of -2.718. 
D)  Yes, because 43 is greater than 41.5.

Question 19

i. Two examples of a hypothesis are: 1) mean monthly income from all sources for senior citizens is
$841 and 2) twenty percent of juvenile offenders ultimately are caught and sentenced to prison.
ii. Hypothesis testing is a procedure based on sample evidence and probability theory to decide
Whether the hypothesis is a reasonable statement.
iii. We call a statement about the value of a population parameter a hypothesis.

Accepted Answer

A)  (i), (ii), and (iii) are all correct statements. 
B)  (i) is a correct statement but not (ii) or (iii). 
C)  (i) and (iii) are correct statements but not (ii). 
D)  (i) and (ii) are correct statements but not (iii). 
E)  (i), (ii), and (iii) are all false statements. 
A)  (i), (ii), and (iii) are all correct statements. 
B)  (i) is a correct statement but not (ii) or (iii). 
C)  (i) and (iii) are correct statements but not (ii). 
D)  (i) and (ii) are correct statements but not (iii). 
E)  (i), (ii), and (iii) are all false statements.

Question 20

The Jamestown Steel Company manufactures and assembles desks and other oﬃce equipment at
Several plants. The weekly production of the Model A325 desk follows a normal probability
Distribution, with a mean of 200 and a standard deviation of 16. Recently, due to market expansion,
New production methods have been introduced and new employees hired. The vice president of
Manufacturing would like to investigate whether there has been an increase in the weekly
Production of the Model A325 desk. The mean number of desks produced last year (50 weeks,
Because the plant was shut down two weeks for vacation) is 203.5. Is the mean number of desks
Increased from 200? Test using the .10 signiﬁcance level.

Accepted Answer

A)  Reject the null hypothesis; there is suﬃcient evidence to indicate an increase in the weekly production. 
B)  Unable to reject the null hypothesis; there is suﬃcient evidence to indicate a change in weekly production. 
C)  Unable to reject the null hypothesis; there is insuﬃcient evidence to indicate an increase in weekly production. 
D)  Reject the null hypothesis; there is insuﬃcient evidence to indicate a change in the weekly production. 
A)  Reject the null hypothesis; there is suﬃcient evidence to indicate an increase in the weekly production. 
B)  Unable to reject the null hypothesis; there is suﬃcient evidence to indicate a change in weekly production. 
C)  Unable to reject the null hypothesis; there is insuﬃcient evidence to indicate an increase in weekly production. 
D)  Reject the null hypothesis; there is insuﬃcient evidence to indicate a change in the weekly production.

If α = 0.05 for a two-tailed test, how large is the acceptance area?

Based on the Nielsen ratings, the local CBS aﬃliate claims its 11 p.m. newscast reaches 41% of the Viewing audience in the area. In a survey of 81 viewers, 36% indicated that they watch the late Evening news on this local CBS station. What is the z test statistic?

Based on the Nielsen ratings, the local CBS aﬃliate claims its 11:00 PM newscast reaches 41% of the Viewing audience in the area. In a survey of 100 viewers, 36% indicated that they watch the late Evening news on this local CBS station. What is the null hypothesis?

What is the critical z-value for a one-tailed lower test at the 1% level of risk?

A restaurant that bills its house account monthly is concerned that the average monthly bill exceeds $200 per account. A random sample of twelve accounts is selected, resulting in a sample mean of $220 and a standard deviation of $12. The t-test is to be conducted at the 5% level of signiﬁcance.

A manufacturer claims that less than 1% of all his products do not meet the minimum government Standards. A survey of 500 products revealed ten did not meet the standard. If the z-statistic is -2)58 and the level of signiﬁcance is 0.02, what is your decision?

A manufacturer claims that less than 1% of all his products do not meet the minimum government Standards. A survey of 500 products revealed ten did not meet the standard. If the z-statistic is -2.054 and the level of signiﬁcance is 0.03, what is your decision?

What must both np and n(1 - p) exceed in testing a hypothesis involving one proportion?

What Is Statistics

Describing Data: Frequencydistributions and Graphic Presentation

Describing Data: Numerical Measures

Describing Data: Displaying and Exploring Pata

A Sulvey of Probability Concepts

Discrete Probability Distributions

Continuous Probabilitydistributions

Sampling Methods and the Central Umit Theorem

One-Sample Tests of Hypothesis

Two Sample Tests of Hypothesis

Analysis of Variance

Linear Regression and Correlation

Multiple Regression and Correlation Analysis

Chi-Square Applications

Decision Making and Payoff Tables in Investment Scenarios

Filters

Exam 9: Estimation and Confidence Intervals

If α = 0.05 for a two-tailed test, how large is the acceptance area?

Based on the Nielsen ratings, the local CBS aﬃliate claims its 11 p.m. newscast reaches 41% of the Viewing audience in the area. In a survey of 81 viewers, 36% indicated that they watch the late Evening news on this local CBS station. What is the z test statistic?

Based on the Nielsen ratings, the local CBS aﬃliate claims its 11:00 PM newscast reaches 41% of the Viewing audience in the area. In a survey of 100 viewers, 36% indicated that they watch the late Evening news on this local CBS station. What is the null hypothesis?

What is the critical z-value for a one-tailed lower test at the 1% level of risk?

A restaurant that bills its house account monthly is concerned that the average monthly bill exceeds $200 per account. A random sample of twelve accounts is selected, resulting in a sample mean of $220 and a standard deviation of $12. The t-test is to be conducted at the 5% level of signiﬁcance.

A manufacturer claims that less than 1% of all his products do not meet the minimum government Standards. A survey of 500 products revealed ten did not meet the standard. If the z-statistic is -2)58 and the level of signiﬁcance is 0.02, what is your decision?

A manufacturer claims that less than 1% of all his products do not meet the minimum government Standards. A survey of 500 products revealed ten did not meet the standard. If the z-statistic is -2.054 and the level of signiﬁcance is 0.03, what is your decision?

What must both np and n(1 - p) exceed in testing a hypothesis involving one proportion?

What Is Statistics

Describing Data: Frequencydistributions and Graphic Presentation

Describing Data: Numerical Measures

Describing Data: Displaying and Exploring Pata

A Sulvey of Probability Concepts

Discrete Probability Distributions

Continuous Probabilitydistributions

Sampling Methods and the Central Umit Theorem

One-Sample Tests of Hypothesis

Two Sample Tests of Hypothesis

Analysis of Variance

Linear Regression and Correlation

Multiple Regression and Correlation Analysis

Chi-Square Applications

Decision Making and Payoff Tables in Investment Scenarios

Filters