Question 1

When testing the difference between two population proportions,__________ test statistic is used.

Accepted Answer

A) Z 
B) t 
C) F 
D) t2 
A) Z 
B) t 
C) F 
D) t2

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.   Write the alternative hypothesis.

Accepted Answer

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

Question 3

When testing H0: $\sigma$12 $\le$ $\sigma$22 HA: $\sigma$12> $\sigma$22 where s12 = .004,s22 = .002,n1 = 4,n2 = 7 at $\alpha$ = .05,what critical value do we use?

Accepted Answer

A) 1.833 
B) 1.796 
C) 4.12 
D) 4.76 
A) 1.833 
B) 1.796 
C) 4.12 
D) 4.76

Question 4

Suppose that a realtor is interested in comparing the price of midrange homes in two cities in a Midwestern state.She conducts a small survey in the two cities looking at the price of midrange homes.Assume equal population variances.   
Calculate the pooled estimate of  $\sigma$2 (rounded to nearest hundred)

Accepted Answer

A) 2100 
B) 4,335,400 
C) 4,932,000 
D) 2200 
A) 2100 
B) 4,335,400 
C) 4,932,000 
D) 2200

Question 5

Two hospital emergency rooms use different procedures for triage of their patients.We want to test the claim that the mean waiting time of patients is the same for both hospitals.The 40 randomly selected subjects from one hospital produce a mean of 18.3 minutes.The 50 randomly selected patients from the other hospital produce a mean of 25.31 minutes.Assume a  $\sigma$a = 2.1 minutes and  $\sigma$b = 2.92 minutes.Setup the null hypothesis to determine if there is a difference in the mean waiting time between the two hospitals.

Accepted Answer

A) µa - µb = 0 B) µa - µb $\neq$ 0 C) µa - µb > 0 D) µa - µb < 0 A) µa - µb = 0 B) µa - µb $\neq$ 0 C) µa - µb > 0 D) µa - µb < 0

Question 6

In a market research study conducted by a local winery on white wine preference,the following results were found.Of a sample of 500 men,120 preferred white wine and of a sample of 500 women,210 preferred white wine.Calculate the test statistic for testing the claim that women are 25% higher than men on preference for white wine.

Accepted Answer

A) 6.167 
B) -82.16 
C) -2.397 
D) -.07 
A) 6.167 
B) -82.16 
C) -2.397 
D) -.07

Question 7

When comparing two population means based on independent random samples,the pooled estimate of the variance is used if both population standard deviations are known.

Accepted Answer

A) True 
 B)False

Question 8

Suppose that a realtor is interested in comparing the price of midrange homes in two cities in a Midwestern state.She conducts a small survey in the two cities looking at the price of midrange homes.Assume equal population variances.   Test the claim at   = .01 where the pooled variance = 4335357.143.

Accepted Answer

A) Can reject the null hypothesis 
B) Cannot reject the null hypothesis 
A) Can reject the null hypothesis 
B) Cannot reject the null hypothesis

Question 9

Suppose that a realtor is interested in comparing the price of midrange homes in two cities in a Midwestern state.She conducts a small survey in the two cities looking at the price of midrange homes.Assume equal population variances.   Setup the alternative hypothesis to test the claim that there is a difference in the mean price of midrange homes of the two cities.

Accepted Answer

A) µa - µb = 0 B) µa - µb $\neq$ 0 C) µa - µb > 0 D) µa - µb < 0 A) µa - µb = 0 B) µa - µb $\neq$ 0 C) µa - µb > 0 D) µa - µb < 0

Question 10

If we are testing the difference between the means of two normally distributed independent populations with samples of n1 = 10,n2 = 10,the degrees of freedom for the t statistic is ____.

Accepted Answer

A) 19 
B) 18 
C) 9 
D) 8 
E) 20 
A) 19 
B) 18 
C) 9 
D) 8 
E) 20

Question 11

When we are testing a hypothesis about the difference in two population proportions based on large independent samples,we compute a combined (pooled)proportion from the two samples if we assume that there is no difference between the two proportions in our null hypothesis.

Accepted Answer

A) True 
 B)False

Question 12

In testing the difference between two means from two independent populations,the sample sizes do not have to be equal to be able to use the Z statistic.

Accepted Answer

A) True 
 B)False

Question 13

A marketing research company surveyed grocery shoppers in the east and west coasts to see the percentage of the customers who prefer chicken to other meat.The data are given below.   Determine the 95% confidence interval for the difference between the proportion of customers who prefer chicken at the West Coast and the proportion of customers who prefer chicken at the East Coast.

Accepted Answer

A) (0.075 0.183) 
B) (0.044 0.213) 
C) (0.096 0.161) 
D) (0.064 0.193) 
A) (0.075 0.183) 
B) (0.044 0.213) 
C) (0.096 0.161) 
D) (0.064 0.193)

Question 14

Parameters of the F distribution include:

Accepted Answer

A) n1 
B) degrees of freedom 
C) n2 
D) A and C 
E) None of the above 
A) n1 
B) degrees of freedom 
C) n2 
D) A and C 
E) None of the above

Question 15

In testing the difference between the means of two independent populations,the variances of the two samples can be pooled if the population variances are assumed to be ____________.

Accepted Answer

A) Unequal 
B) Greater than the mean 
C) Sum to 1 
D) Equal 
A) Unequal 
B) Greater than the mean 
C) Sum to 1 
D) Equal

Question 16

Determine the 95% 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

A) (-0.16 4.76) 
B) (-0.58 5.18) 
C) (0.01 4.59) 
D) (0.56 4.04) 
A) (-0.16 4.76) 
B) (-0.58 5.18) 
C) (0.01 4.59) 
D) (0.56 4.04)

Question 17

A test of spelling ability is given to a random sample of 10 students before and after they completed a spelling course.The mean score before the course was 119.60 and after the course the mean score was 130.80.The standard deviation of the difference was 16.061.Calculate a 99% confidence interval.

Accepted Answer

A) (-3.13 25.53) 
B) (6.12 16.28) 
C) (-1.88 24.28) 
D) (-5.31 27.71) 
A) (-3.13 25.53) 
B) (6.12 16.28) 
C) (-1.88 24.28) 
D) (-5.31 27.71)

Question 18

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.   
Is there evidence at $\alpha$ = .05 to conclude that the new training method is more effective than the traditional training method?

Accepted Answer

A) Yes,there is evidence to reject the null hypothesis 
B) No,there is not sufficient evidence to reject the null hypothesis 
A) Yes,there is evidence to reject the null hypothesis 
B) No,there is not sufficient evidence to reject the null hypothesis

Question 19

A marketing research company surveyed grocery shoppers in the east and west coasts to see the percentage of the customers who prefer chicken to other meat.The data are given below.  
 Is the proportion of customers who prefer chicken the same for the two regions? Test at $\alpha$ = .10.

Accepted Answer

A) Reject the null hypothesis 
B) Can't reject the null hypothesis 
A) Reject the null hypothesis 
B) Can't reject the null hypothesis

Question 20

Construct a 95 percent confidence interval for $\mu$1- v2,where   1 = 34.36,   2 = 26.45,s1 = 9,s2= 6,n1 = 10,n2 = 16.(Assume equal population variance)

Accepted Answer

A) (1.59 14.23) 
B) (2.10 13.72) 
C) (1.86 13.96) 
D) (1.88 13.94) 
A) (1.59 14.23) 
B) (2.10 13.72) 
C) (1.86 13.96) 
D) (1.88 13.94)

When testing the difference between two population proportions,__________ test statistic is used.

When testing H₀: $\sigma$ ₁² $\le$ $\sigma$ ₂² H_A: $\sigma$ ₁²> $\sigma$ ₂² where s₁² = .004,s₂² = .002,n₁ = 4,n₂ = 7 at $\alpha$ = .05,what critical value do we use?

When comparing two population means based on independent random samples,the pooled estimate of the variance is used if both population standard deviations are known.

Suppose that a realtor is interested in comparing the price of midrange homes in two cities in a Midwestern state.She conducts a small survey in the two cities looking at the price of midrange homes.Assume equal population variances. Test the claim at = .01 where the pooled variance = 4335357.143.

If we are testing the difference between the means of two normally distributed independent populations with samples of n₁ = 10,n₂ = 10,the degrees of freedom for the t statistic is ____.

When we are testing a hypothesis about the difference in two population proportions based on large independent samples,we compute a combined (pooled)proportion from the two samples if we assume that there is no difference between the two proportions in our null hypothesis.

In testing the difference between two means from two independent populations,the sample sizes do not have to be equal to be able to use the Z statistic.

Parameters of the F distribution include:

In testing the difference between the means of two independent populations,the variances of the two samples can be pooled if the population variances are assumed to be ____________.

Determine the 95% 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)

A test of spelling ability is given to a random sample of 10 students before and after they completed a spelling course.The mean score before the course was 119.60 and after the course the mean score was 130.80.The standard deviation of the difference was 16.061.Calculate a 99% confidence interval.

An Introduction to Business Statistics

Descriptive Statistics: Tabular and Graphical Methods

Descriptive Statistics: Numerical Methods

Probability

Discrete Random Variables

Continuous Random Variables

Sampling and Sampling Distributions

Confidence Intervals

Hypothesis Testing

Experimental Design and Analysis of Variance

Chi-Square Tests

Simple Linear Regression Analysis

Multiple Regression

Model Building and Model Diagnostics

Time Series Forecasting

Process Improvement Using Control Charts

Nonparametric Methods

Decision Theory

Filters

Exam 10: Statistical Inferences Based on Two Samples

When testing the difference between two population proportions,__________ test statistic is used.

When testing H0: σ\sigmaσ 12 ≤\le≤ σ\sigmaσ 22 HA: σ\sigmaσ 12> σ\sigmaσ 22 where s12 = .004,s22 = .002,n1 = 4,n2 = 7 at α\alphaα = .05,what critical value do we use?

When comparing two population means based on independent random samples,the pooled estimate of the variance is used if both population standard deviations are known.

Suppose that a realtor is interested in comparing the price of midrange homes in two cities in a Midwestern state.She conducts a small survey in the two cities looking at the price of midrange homes.Assume equal population variances. Test the claim at = .01 where the pooled variance = 4335357.143.

If we are testing the difference between the means of two normally distributed independent populations with samples of n1 = 10,n2 = 10,the degrees of freedom for the t statistic is ____.

When we are testing a hypothesis about the difference in two population proportions based on large independent samples,we compute a combined (pooled)proportion from the two samples if we assume that there is no difference between the two proportions in our null hypothesis.

In testing the difference between two means from two independent populations,the sample sizes do not have to be equal to be able to use the Z statistic.

Parameters of the F distribution include:

In testing the difference between the means of two independent populations,the variances of the two samples can be pooled if the population variances are assumed to be ____________.

Determine the 95% 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)

A test of spelling ability is given to a random sample of 10 students before and after they completed a spelling course.The mean score before the course was 119.60 and after the course the mean score was 130.80.The standard deviation of the difference was 16.061.Calculate a 99% confidence interval.

A marketing research company surveyed grocery shoppers in the east and west coasts to see the percentage of the customers who prefer chicken to other meat.The data are given below. Is the proportion of customers who prefer chicken the same for the two regions? Test at α\alphaα = .10.

Construct a 95 percent confidence interval for μ\muμ 1- v2,where 1 = 34.36, 2 = 26.45,s1 = 9,s2= 6,n1 = 10,n2 = 16.(Assume equal population variance)

An Introduction to Business Statistics

Descriptive Statistics: Tabular and Graphical Methods

Descriptive Statistics: Numerical Methods

Probability

Discrete Random Variables

Continuous Random Variables

Sampling and Sampling Distributions

Confidence Intervals

Hypothesis Testing

Experimental Design and Analysis of Variance

Chi-Square Tests

Simple Linear Regression Analysis

Multiple Regression

Model Building and Model Diagnostics

Time Series Forecasting

Process Improvement Using Control Charts

Nonparametric Methods

Decision Theory

Filters

When testing H₀: $\sigma$ ₁² $\le$ $\sigma$ ₂² H_A: $\sigma$ ₁²> $\sigma$ ₂² where s₁² = .004,s₂² = .002,n₁ = 4,n₂ = 7 at $\alpha$ = .05,what critical value do we use?

If we are testing the difference between the means of two normally distributed independent populations with samples of n₁ = 10,n₂ = 10,the degrees of freedom for the t statistic is ____.