Question 1

When we test H₀: μ₁ - μ₂ ≤ 0,H_A: μ₁ - μ₂ > 0, $\bar { X } _ { 1 }$ = 15.4, $\bar { X} _ { 2 }$ = 14.5,σ₁ = 2,σ₂ = 2.28,n₁ = 35,and n₂ = 18 at α = .01,what is the value of the test statistic?

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Question 2

A fast food company uses two management-training methods.Method 1 is a traditional method of training and Method 2 is a new and innovative method.The company has just hired 31 new management trainees.15 of the trainees are randomly selected and assigned to the first method,and the remaining 16 trainees are assigned to the second training method.After three months of training,the management trainees took a standardized test.The test was designed to evaluate their performance and learning from training.The sample mean score and sample standard deviation of the two methods are given below.The management wants to determine if the company should implement the new training method.
$\begin{array}{lcc} 
& \text { Mean } & \text { Standard Deviation } \
\text { Method 1 } & 69 & 3.4 \
\text { Method 2 } & 72 & 3.8
\end{array}$ 
Is there evidence at α = .05 to conclude that the new training method is more effective than the traditional training method?

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Question 3

Let p₁ represent the population proportion of U.S.senatorial and congressional (House of Representatives)Democrats who are in favor of a new modest tax on "junk food".Let p₂ represent the population proportion of U.S.senatorial and congressional Republicans who are in favor of a new modest tax on "junk food." Out of the 265 Democratic senators and members of Congress,106 of them are in favor of a "junk food" tax.Out of the 285 Republican senators and members of Congress,only 57 are in favor a "junk food" tax.At α = .01,can we conclude that the proportion of Democrats who favor a "junk food" tax is more than 5 percent higher than the proportion of Republicans who favor the new tax?

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Question 4

Find a 99 percent confidence interval for the difference between means,given that n₁ = 49,n₂ = 49,

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Question 5

Calculate the t statistic for testing equality of means where

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Question 6

At α = .10,testing the hypothesis that the proportion of consumer industry companies' (CON)winter-quarter profit growth is more than 2 percent greater than the proportion of banking companies' (BKG)winter-quarter profit growth,given that $\hat { p }_{ C O N }= .20$ $\hat { p } _{B K G} = .14$ n_CON = 300,and n_BKG = 400,can we reject the null hypothesis?

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Question 7

A fast-food company uses two management-training methods.Method 1 is a traditional method of training,and Method 2 is a new and innovative method.The company has just hired 31 new management trainees.15 of the trainees are randomly selected and assigned to Method 1,and the remaining 16 trainees are assigned to Method 1 .After three months of training,the management trainees take a standardized test.The test is designed to evaluate their performance and learning from the training.The sample mean score and sample standard deviation of the two methods are given below.Company management wants to determine whether the company should implement the new training method.
$\begin{array}{lcc} 
& \text { Mean } & \text { Standard Deviation } \
\text { Method 1 } & 69 & 3.4 \
\text { Method 2 } & 72 & 3.8
\end{array}$ 
What is the absolute value of the rejection point (critical value of the test statistic)at α = .05?

Accepted Answer

The answer of A fast-food company uses two management-training methods.Method...

Question 8

At α = .10,testing the hypothesis that the proportion of consumer industry companies' (CON)winter-quarter profit growth is more than 2 percent greater than the proportion of banking companies' (BKG)winter-quarter profit growth,given that $\hat { p }_{ CON } = .20 ,$ $\hat { p } _ { B K G } = .14 ,$ n_CON = 300,and n_BKG = 400,calculate the estimated standard deviation for the model.

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The answer of At α = .10,testing the hypothesis that...

Question 9

A fast-food company uses two management-training methods.Method 1 is a traditional method of training,and Method 2 is a new and innovative method.The company has just hired 31 new management trainees.15 of the trainees are randomly selected and assigned to Method 1,and the remaining 16 trainees are assigned to Method 2.After three months of training,the management trainees take a standardized test.The test is designed to evaluate their performance and learning from the training.The sample mean score and sample standard deviation of the two methods are given below.Company management wants to determine whether the company should implement the new training method.
$\begin{array}{lcc} 
& \text { Mean } & \text { Standard Deviation } \
\text { Method 1 } & 69 & 3.4 \
\text { Method 2 } & 72 & 3.8
\end{array}$ 
Write the null and alternative hypotheses.

Accepted Answer

The answer of A fast-food company uses two management-training methods.Method...

Question 10

When we test H₀: μ₁ - μ₂ ≤ 0,H_A: μ₁ - μ₂ > 0, $\bar { X }_ { 1 }$ = 15.4, $\bar { X }_ { 1 }$ = 14.5,s₁ = 2,s₂ = 2.28,n₁ = 35,and n₂ = 18 at α = .01,can we reject the null hypothesis? (Assume unequal variances. )

Accepted Answer

The answer of When we test H₀: μ₁ - μ₂...

Question 11

Find a 95 percent confidence interval for μ₁ - μ₂,where n₁ = 9,n₂ = 6, $\bar { X } _ { 1 } = 64$ $\bar { X } _ { 2 } = 59$ s₁² = 6,and s₂² = 3.(Assume equal population variances. )

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Question 12

In an opinion survey,a random sample of 1000 adults from the United States and 1000 adults from Germany were asked whether they supported the death penalty.590 American adults and 560 German adults indicated that they supported the death penalty.The researcher wants to know whether there is sufficient evidence to conclude that the proportion of adults who support the death penalty is higher in the United States than in Germany.What is the rejection point (critical value of the test statistic)at α = .10?

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Question 13

Let p₁ represent the population proportion of U.S.senatorial and congressional (House of Representatives)Democrats who are in favor of a new modest tax on "junk food." Let p₂ represent the population proportion of U.S.senatorial and congressional Republicans who are in favor of a new modest tax on "junk food." Out of the 265 Democratic senators and members of Congress,106 of them are in favor of a "junk food" tax.Out of the 285 Republican senators and members of Congress,only 57 are in favor of a "junk food" tax.Find a 95 percent confidence interval for the difference between proportions l and 2.

Accepted Answer

The answer of Let p₁ represent the population proportion of...

Question 14

Calculate the pooled variance where sample 1 has data: 16,14,19,18,19,20,15,18,17,18;and sample 2 has data: 13,19,14,17,21,14,15,10,13,15.

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Question 15

A fast food company uses two management-training methods.Method 1 is a traditional method of training and Method 2 is a new and innovative method.The company has just hired 31 new management trainees.15 of the trainees are randomly selected and assigned to the first method,and the remaining 16 trainees are assigned to the second training method.After three months of training,the management trainees took a standardized test.The test was designed to evaluate their performance and learning from training.The sample mean score and sample standard deviation of the two methods are given below.The management wants to determine if the company should implement the new training method.
$\begin{array}{lcc} 
& \text { Mean } & \text { Standard Deviation } \
\text { Method 1 } & 69 & 3.4 \
\text { Method 2 } & 72 & 3.8
\end{array}$ 
What is the sample value of the test statistic?

Accepted Answer

The answer of A fast food company uses two management-training...

Question 16

A fast food company uses two management-training methods.Method 1 is a traditional method of training and Method 2 is a new and innovative method.The company has just hired 31 new management trainees.15 of the trainees are randomly selected and assigned to the first method,and the remaining 16 trainees are assigned to the second training method.After three months of training,the management trainees took a standardized test.The test was designed to evaluate their performance and learning from training.The sample mean score and sample standard deviation of the two methods are given below.The management wants to determine if the company should implement the new training method.
$\begin{array}{lcc} 
& \text { Mean } & \text { Standard Deviation } \
\text { Method 1 } & 69 & 3.4 \
\text { Method 2 } & 72 & 3.8
\end{array}$ 
What is the absolute value of the rejection point (critical value of the test statistic)at α = .01?

Accepted Answer

The answer of A fast food company uses two management-training...

Question 17

A fast food company uses two management-training methods.Method 1 is a traditional method of training and Method 2 is a new and innovative method.The company has just hired 31 new management trainees.15 of the trainees are randomly selected and assigned to the first method,and the remaining 16 trainees are assigned to the second training method.After three months of training,the management trainees took a standardized test.The test was designed to evaluate their performance and learning from training.The sample mean score and sample standard deviation of the two methods are given below.The management wants to determine if the company should implement the new training method.
$\begin{array}{lcc} 
& \text { Mean } & \text { Standard Deviation } \
\text { Method 1 } & 69 & 3.4 \
\text { Method 2 } & 72 & 3.8
\end{array}$ 
Is there evidence at α = .01 to conclude that the new training method is more effective than the traditional training method?

Accepted Answer

The answer of A fast food company uses two management-training...

Question 18

Testing the equality of means at α = .05,where sample 1 has data: 16,14,19,18,19,20,15,18,17,18;and sample 2 has data: 13,19,14,17,21,14,15,10,13,15,can we reject the null hypothesis? (Assume equal population variances. )

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The answer of Testing the equality of means at α...

Question 19

Find a 90 percent confidence interval for the difference between the proportions of group l and group 2.Let p₁ represent the population proportion of the people in group 1 who are in favor of new packaging,and let p₂ represent the population proportion of the people in group 2 who are in favor of new packaging. $\hat { p } _ { 1 }$ = .21, $\hat { p } _ { 2 }$ = .13,n₁ = 300,and n₂ = 400.

Accepted Answer

The answer of Find a 90 percent confidence interval for...

Question 20

Determine the 95 percent confidence interval for the difference between two population means,where sample 1 has data: 16,14,19,18,19,20,15,18,17,18;and sample 2 has data: 13,19,14,17,21,14,15,10,13,15.(Assume equal population variances. )

Accepted Answer

The answer of Determine the 95 percent confidence interval for...

Quiz 10: Comparing Two Means and Two Proportions

When we test H0: μ1 - μ2 ≤ 0,HA: μ1 - μ2 > 0, Xˉ1\bar { X } _ { 1 }Xˉ1​ = 15.4, Xˉ2\bar { X} _ { 2 }Xˉ2​ = 14.5,σ1 = 2,σ2 = 2.28,n1 = 35,and n2 = 18 at α = .01,what is the value of the test statistic?

Find a 99 percent confidence interval for the difference between means,given that n1 = 49,n2 = 49,

Calculate the t statistic for testing equality of means where

When we test H0: μ1 - μ2 ≤ 0,HA: μ1 - μ2 > 0, Xˉ1\bar { X }_ { 1 }Xˉ1​ = 15.4, Xˉ1\bar { X }_ { 1 }Xˉ1​ = 14.5,s1 = 2,s2 = 2.28,n1 = 35,and n2 = 18 at α = .01,can we reject the null hypothesis? (Assume unequal variances. )

Find a 95 percent confidence interval for μ1 - μ2,where n1 = 9,n2 = 6, Xˉ1=64\bar { X } _ { 1 } = 64Xˉ1​=64 Xˉ2=59\bar { X } _ { 2 } = 59Xˉ2​=59 s12 = 6,and s22 = 3.(Assume equal population variances. )

Calculate the pooled variance where sample 1 has data: 16,14,19,18,19,20,15,18,17,18;and sample 2 has data: 13,19,14,17,21,14,15,10,13,15.

Testing the equality of means at α = .05,where sample 1 has data: 16,14,19,18,19,20,15,18,17,18;and sample 2 has data: 13,19,14,17,21,14,15,10,13,15,can we reject the null hypothesis? (Assume equal population variances. )

Determine the 95 percent confidence interval for the difference between two population means,where sample 1 has data: 16,14,19,18,19,20,15,18,17,18;and sample 2 has data: 13,19,14,17,21,14,15,10,13,15.(Assume equal population variances. )

When we test H₀: μ₁ - μ₂ ≤ 0,H_A: μ₁ - μ₂ > 0, $\bar { X } _ { 1 }$ = 15.4, $\bar { X} _ { 2 }$ = 14.5,σ₁ = 2,σ₂ = 2.28,n₁ = 35,and n₂ = 18 at α = .01,what is the value of the test statistic?

Find a 99 percent confidence interval for the difference between means,given that n₁ = 49,n₂ = 49,

When we test H₀: μ₁ - μ₂ ≤ 0,H_A: μ₁ - μ₂ > 0, $\bar { X }_ { 1 }$ = 15.4, $\bar { X }_ { 1 }$ = 14.5,s₁ = 2,s₂ = 2.28,n₁ = 35,and n₂ = 18 at α = .01,can we reject the null hypothesis? (Assume unequal variances. )

Find a 95 percent confidence interval for μ₁ - μ₂,where n₁ = 9,n₂ = 6, $\bar { X } _ { 1 } = 64$ $\bar { X } _ { 2 } = 59$ s₁² = 6,and s₂² = 3.(Assume equal population variances. )