Question 1

The statistic (n − 1)s2 / σ2 has a chi-squared distribution with n − 1 degrees of freedom if:

Accepted Answer

A) the sample has a Student t-distribution with degrees of freedom equal to n − 1. 
B) the sample is normally distributed with variance equal to s2. 
C) the population is normally distributed with variance equal to σ2. 
D) All of these choices are true. 
A) the sample has a Student t-distribution with degrees of freedom equal to n − 1. 
B) the sample is normally distributed with variance equal to s2. 
C) the population is normally distributed with variance equal to σ2. 
D) All of these choices are true.

Question 2

Tractor Dealership
 An accountant was performing an audit for a tractor dealership.An auditor wants to examine the monetary error made by the purchasing order department in the month of July.He decided to randomly sample 100 of the 925 purchase orders for the month of July,and found the amount of error in each one.The statistics for this sample were:   = $6.0 and s = $17.012. ​ ​
-{Tractor Dealership Narrative} Estimate with 95% confidence the average amount of error per purchase order for the entire month of July.

Accepted Answer

@#IMG-DLM& LCL = $2.81,and UCL

Question 3

Socialist Party Voters
 A pollster in Italy wants to challenge a claim that 5% of the registered voters in his country are Socialists; he thinks the percentage is lower than that.In a test of hypothesis,HS1U1B10S1U1B0: p = 0.05 vs.HS1U1B11S1U1B0: p < 0.05,his random sample of size 1,000 registered voters revealed that the number of Socialists was 40. ​ ​
-{Socialist Voters Narrative} Test the hypotheses at the 5% significance level.

Accepted Answer

Rejection region: z < −z_0.05 = −1.

Question 4

The test statistic for p is approximately normal when np and n(1 − p)are both ____________________.

Accepted Answer

The answer of The test statistic for p is approximately...

Question 5

The t-statistic has two variables: the sample ____________________ and the sample ____________________.

Accepted Answer

mean; standard devia

Question 6

When is the finite population correction used?

Accepted Answer

A) When the population is more than or equal to 20 times the sample size. 
B) When the population is less than or equal to 20 times the population size. 
C) When the population is equal to 20 times the population size. 
D) Whenever the sample size is small,no matter what the population size is. 
A) When the population is more than or equal to 20 times the sample size. 
B) When the population is less than or equal to 20 times the population size. 
C) When the population is equal to 20 times the population size. 
D) Whenever the sample size is small,no matter what the population size is.

Question 7

In a hypothesis test for the population variance,the hypotheses are H0: σ2 = 100 vs.H1: σ2 ≠ 100.If the sample size is 15 and the test is being carried out at the 10% level of significance,the rejection region is:

Accepted Answer

A) χ2 2 > 23.685. B) χ2 2 > 21.064. C) χ2 2 > 22.307. D) χ2 2 < 24.996. A) χ2 2 > 23.685. B) χ2 2 > 21.064. C) χ2 2 > 22.307. D) χ2 2 < 24.996.

Question 8

After calculating the sample size needed to estimate a population proportion to within 0.04,your statistics professor told you the maximum allowable error must be reduced to just .01.If the original calculation led to a sample size of 800,the sample size will now have to be:

Accepted Answer

A) 800 
B) 3,200 
C) 6,400 
D) 12,800 
A) 800 
B) 3,200 
C) 6,400 
D) 12,800

Question 9

A left-tailed area in the chi-squared distribution equals 0.95.For 6 degrees of freedom the critical value equals 12.592.

Accepted Answer

A) True 
 B)False

Question 10

Socialist Party Voters
 A pollster in Italy wants to challenge a claim that 5% of the registered voters in his country are Socialists; he thinks the percentage is lower than that.In a test of hypothesis,HS1U1B10S1U1B0: p = 0.05 vs.HS1U1B11S1U1B0: p < 0.05,his random sample of size 1,000 registered voters revealed that the number of Socialists was 40. ​ ​
-{Socialist Voters Narrative} Compute the p-value and explain how to use it to test the hypotheses.

Accepted Answer

p-value = 0.0735. Si

Question 11

Tire Rotation
 The manager of a service station is in the process of analyzing the number of times car owners rotate the tires on their cars.She believes that the average motorist rotates his or her car's tires less frequently than recommended by the owner's manual (two times per year).In a preliminary survey she asked 14 car owners how many times they rotated their cars' tires in the last 12 months.The results are 1,1,2,0,3,3,0,1,0,1,2,3,3,and 1. ​ ​
-{Tire Rotation Narrative} Does this data provide sufficient evidence at the 10% significance level to indicate that the manager is correct?

Accepted Answer

H₀: μ = 2,H₁: μ < 2 Rejection r

Question 12

The sum of squared deviations from the mean divided by the population variance has a(n)____________________ distribution with ____________________ degrees of freedom.

Accepted Answer

chi-square

Question 13

Sinus Drug
 A company claims that 10% of the users of a certain sinus drug experience drowsiness.In clinical studies of this sinus drug,81 of the 900 subjects experienced drowsiness ​ ​
-{Sinus Drug Narrative} Compute the p-value of the test.

Accepted Answer

The answer of Sinus Drug
 A company claims that 10%...

Question 14

Healthy Foods
 In segmenting the frozen meal market in Spain,a food manufacturer uses health and diet consciousness as the segmentation variable.Four segments are developed and coded as follows: 1: Concerned about eating healthy foods 2: Concerned about weight 3: Concerned about health because of illness 4: Unconcerned To distinguish between groups,surveys are conducted.On the basis of a questionnaire,people are categorized as belonging to one of these groups.A recent survey asked a random sample of 1,500 Spanish adults (20 and over)to complete the survey.Out of the 1,500 people surveyed,360 indicated that they are concerned about eating healthy foods.The most recent information available reveals that there are 40,256,000 Spanish adults who are 20 and over. ​ ​
-{Healthy Foods Narrative} Interpret the confidence interval of p.

Accepted Answer

We estimate that the proportio

Question 15

Mass Marketing refers to the mass production and marketing by a company of a single product for the entire market.

Accepted Answer

A) True 
 B)False

Question 16

A race car driver tested his car for time from 0 to 60 mph,and in 20 tests obtained an average of 48.5 seconds with a standard deviation of 1.47 seconds.A 95% confidence interval for the 0 to 60 time is 45.2 seconds to 51.8 seconds.

Accepted Answer

A) True 
 B)False

Question 17

Mystic Pizza 
Mystic Pizza in Mystic,Connecticut,advertises that they deliver your pizza within 15 minutes of placing an order or it is free.A sample of 25 customers is selected at random.The average delivery time in the sample was 13 minutes with a sample standard deviation of 4 minutes. ​ ​
-{Mystic Pizza Narrative} We want to know whether Mystic can make this claim or not.Test to determine if we can infer at the 5% significance level that the population mean delivery time is less than 15 minutes.

Accepted Answer

H₀: μ = 15,H₁: μ < 15 Rejection

Question 18

Which of the following statements is false?

Accepted Answer

A) Because there is one single way to segment a market,managers must consider several variable or characteristics that could be used to identify segments. 
B) Surveys of customers are used to gather data about various aspects of the market. 
C) Statistical techniques are applied to the survey data to define the market segments. 
D) Market segmentation separates consumers of a product into different groups in such a way that members of each group are similar to each other and there are differences between groups. 
A) Because there is one single way to segment a market,managers must consider several variable or characteristics that could be used to identify segments. 
B) Surveys of customers are used to gather data about various aspects of the market. 
C) Statistical techniques are applied to the survey data to define the market segments. 
D) Market segmentation separates consumers of a product into different groups in such a way that members of each group are similar to each other and there are differences between groups.

Question 19

Market segmentation separates consumers of a product into different groups in such a way that members of each group are similar to each other and there are differences between groups.

Accepted Answer

A) True 
 B)False

Question 20

An investor is concerned with the risk associated with a portfolio of stocks.He draws a random sample of nine monthly returns (expressed as a percentage of the initial investment).These data follow: 2,5,−6,10,1,2,−3,0,and 7.Find a 95% confidence interval estimate of the population variance.

Accepted Answer

LCL = 10.9

The statistic (n − 1)s² / σ² has a chi-squared distribution with n − 1 degrees of freedom if:

The test statistic for p is approximately normal when np and n(1 − p)are both ____________________.

The t-statistic has two variables: the sample and the sample .

When is the finite population correction used?

In a hypothesis test for the population variance,the hypotheses are H₀: σ² = 100 vs.H₁: σ² ≠ 100.If the sample size is 15 and the test is being carried out at the 10% level of significance,the rejection region is:

After calculating the sample size needed to estimate a population proportion to within 0.04,your statistics professor told you the maximum allowable error must be reduced to just .01.If the original calculation led to a sample size of 800,the sample size will now have to be:

A left-tailed area in the chi-squared distribution equals 0.95.For 6 degrees of freedom the critical value equals 12.592.

The sum of squared deviations from the mean divided by the population variance has a(n) distribution with degrees of freedom.

Sinus Drug A company claims that 10% of the users of a certain sinus drug experience drowsiness.In clinical studies of this sinus drug,81 of the 900 subjects experienced drowsiness -{Sinus Drug Narrative} Compute the p-value of the test.

Mass Marketing refers to the mass production and marketing by a company of a single product for the entire market.

A race car driver tested his car for time from 0 to 60 mph,and in 20 tests obtained an average of 48.5 seconds with a standard deviation of 1.47 seconds.A 95% confidence interval for the 0 to 60 time is 45.2 seconds to 51.8 seconds.

Which of the following statements is false?

Market segmentation separates consumers of a product into different groups in such a way that members of each group are similar to each other and there are differences between groups.

An investor is concerned with the risk associated with a portfolio of stocks.He draws a random sample of nine monthly returns (expressed as a percentage of the initial investment).These data follow: 2,5,−6,10,1,2,−3,0,and 7.Find a 95% confidence interval estimate of the population variance.

What Is Statistics

Graphical Descriptive Techniques 1

Graphical Descriptive Techniques 2

Numerical Descriptive Techniques

Data Collection and Sampling

Probability

Random Variables and Discrete Probability Distributions

Continuous Probability Distributions

Sampling Distributions

Introduction to Estimation

Introduction to Hypothesis Testing

Inference About Comparing Two Populations

Analysis of Variance

Chi-Squared Tests

Simple Linear Regression and Correlation

Multiple Regression

Model Building

Nonparametric Statistics

Time-Series Analytics and Forecasting

Statistical Process Control

Decision Analysis

Conclusion

Filters

Exam 12: Inference About a Population

The statistic (n − 1)s2 / σ2 has a chi-squared distribution with n − 1 degrees of freedom if:

The test statistic for p is approximately normal when np and n(1 − p)are both ____________________.

The t-statistic has two variables: the sample ____________________ and the sample ____________________.

When is the finite population correction used?

In a hypothesis test for the population variance,the hypotheses are H0: σ2 = 100 vs.H1: σ2 ≠ 100.If the sample size is 15 and the test is being carried out at the 10% level of significance,the rejection region is:

After calculating the sample size needed to estimate a population proportion to within 0.04,your statistics professor told you the maximum allowable error must be reduced to just .01.If the original calculation led to a sample size of 800,the sample size will now have to be:

A left-tailed area in the chi-squared distribution equals 0.95.For 6 degrees of freedom the critical value equals 12.592.

The sum of squared deviations from the mean divided by the population variance has a(n)____________________ distribution with ____________________ degrees of freedom.

Sinus Drug A company claims that 10% of the users of a certain sinus drug experience drowsiness.In clinical studies of this sinus drug,81 of the 900 subjects experienced drowsiness ​ ​ -{Sinus Drug Narrative} Compute the p-value of the test.

Mass Marketing refers to the mass production and marketing by a company of a single product for the entire market.

A race car driver tested his car for time from 0 to 60 mph,and in 20 tests obtained an average of 48.5 seconds with a standard deviation of 1.47 seconds.A 95% confidence interval for the 0 to 60 time is 45.2 seconds to 51.8 seconds.

Which of the following statements is false?

Market segmentation separates consumers of a product into different groups in such a way that members of each group are similar to each other and there are differences between groups.

An investor is concerned with the risk associated with a portfolio of stocks.He draws a random sample of nine monthly returns (expressed as a percentage of the initial investment).These data follow: 2,5,−6,10,1,2,−3,0,and 7.Find a 95% confidence interval estimate of the population variance.

What Is Statistics

Graphical Descriptive Techniques 1

Graphical Descriptive Techniques 2

Numerical Descriptive Techniques

Data Collection and Sampling

Probability

Random Variables and Discrete Probability Distributions

Continuous Probability Distributions

Sampling Distributions

Introduction to Estimation

Introduction to Hypothesis Testing

Inference About Comparing Two Populations

Analysis of Variance

Chi-Squared Tests

Simple Linear Regression and Correlation

Multiple Regression

Model Building

Nonparametric Statistics

Time-Series Analytics and Forecasting

Statistical Process Control

Decision Analysis

Conclusion

Filters

The statistic (n − 1)s² / σ² has a chi-squared distribution with n − 1 degrees of freedom if:

The t-statistic has two variables: the sample and the sample .

In a hypothesis test for the population variance,the hypotheses are H₀: σ² = 100 vs.H₁: σ² ≠ 100.If the sample size is 15 and the test is being carried out at the 10% level of significance,the rejection region is:

The sum of squared deviations from the mean divided by the population variance has a(n) distribution with degrees of freedom.

Sinus Drug A company claims that 10% of the users of a certain sinus drug experience drowsiness.In clinical studies of this sinus drug,81 of the 900 subjects experienced drowsiness -{Sinus Drug Narrative} Compute the p-value of the test.