Exam 12: Inference About a Population

Researchers determined that 60 Puffs tissues is the average number of tissues used during a cold.Suppose a random sample of 100 Puffs users yielded the following data on the number of tissues used during a cold: = 52 and s = 22.Suppose the test statistic does not fall in the rejection region at α = 0.05.Which of the following conclusions is correct?

(Multiple Choice)

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Question 21

Science Quiz Scores Consider the hypotheses H₀: σ² = 20 vs.H₁: σ² > 20.Assume that Science scores on a 25-point quiz for a random sample of 5 students were drawn from a normal population.These were: 18,16,10,13,and 23. -{Science Quiz Scores Narrative} Test the hypotheses at the 10% significance level.

(Essay)

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Question 22

In testing a hypothesis about a population proportion p,the z test statistic measures how close the computed sample proportion has come to the hypothesized population parameter.

(True/False)

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Question 23

The test statistic used to test hypotheses about the population variance is given by χ² = (n − 1)s² / σ²,which is chi-squared distributed with n − 1 degrees of freedom when the population random variable is normally distributed with variance equal to σ².

(True/False)

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Question 24

For statistical inference about the mean of a single population when the population standard deviation is unknown,the degrees for freedom for the t-distribution equal n − 1 because we lose one degree of freedom by using the:

(Multiple Choice)

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Question 25

A random sample of size 16 taken from a normally distributed population revealed a sample mean of 50 and a sample variance of 36.The upper limit of a 95% confidence interval for the population mean would equal:

(Multiple Choice)

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Question 26

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} We want to test their claim and find out whether the actual percentage is not 10%.State the appropriate null and hypotheses.

(Essay)

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Question 27

Applicants' Grades The grades of a sample of 10 applicants,selected at random from a large population,are 71,86,75,63,92,70,81,59,80,and 90. -{Applicants' Grades Narrative} Construct a 90% confidence interval estimate for the population variance.

(Essay)

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Question 28

From a sample of 400 items,14 are found to be defective.The point estimate of the population proportion defective will be:

(Multiple Choice)

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Question 29

The ____________________ confidence limit of the confidence interval estimator of the population variance is .

(Short Answer)

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Question 30

The formula is used to find the ____________________ to estimate a population proportion.

(Short Answer)

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Question 31

A random sample of 25 observations is selected from a normally distributed population.The sample variance is 10.In the 95% confidence interval for the population variance,the upper limit is:

(Multiple Choice)

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Question 32

Pilots' Union Contract A union composed of several thousand pilots is preparing to vote on a new contract.A random sample of 500 pilots yielded 320 who planned to vote yes.It is believed that the new contract will receive more than 60% yes votes. -{Pilots' Union Contract Narrative} State the appropriate null and alternative hypotheses.

(Essay)

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Question 33

The ____________________ confidence limit of the confidence interval estimator of the population variance is .

(Short Answer)

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Question 34

The t-test for a population mean is ____________________,meaning that if the population is nonnormal,the results of the test and confidence interval are still valid as long as the nonnormality is not extreme.

(Short Answer)

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Question 35

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} What condition is required in order to analyze this data using a t-test?

(Essay)

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Question 36

The area to the right of a certain critical value on a chi-squared distribution is 0.025.For 5 degrees of freedom,the critical value is 11.143.

(True/False)

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Question 37

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} Construct a 95% confidence interval estimate of the population proportion of the users of this allergy drug who experience drowsiness.

(Essay)

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Question 38

The statistic when the sampled population is normal is Student t-distributed with n degrees of freedom.

(True/False)

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Question 39

To test to see if the majority of the population exhibits a certain characteristic of interest,the alternative hypothesis of the test is H₁: p ____________________.

(Short Answer)

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Question 40

Showing 21 - 40 of 153

In testing a hypothesis about a population proportion p,the z test statistic measures how close the computed sample proportion has come to the hypothesized population parameter.

The test statistic used to test hypotheses about the population variance is given by χ² = (n − 1)s² / σ²,which is chi-squared distributed with n − 1 degrees of freedom when the population random variable is normally distributed with variance equal to σ².

For statistical inference about the mean of a single population when the population standard deviation is unknown,the degrees for freedom for the t-distribution equal n − 1 because we lose one degree of freedom by using the:

A random sample of size 16 taken from a normally distributed population revealed a sample mean of 50 and a sample variance of 36.The upper limit of a 95% confidence interval for the population mean would equal:

Applicants' Grades The grades of a sample of 10 applicants,selected at random from a large population,are 71,86,75,63,92,70,81,59,80,and 90. -{Applicants' Grades Narrative} Construct a 90% confidence interval estimate for the population variance.

From a sample of 400 items,14 are found to be defective.The point estimate of the population proportion defective will be:

The ____________________ confidence limit of the confidence interval estimator of the population variance is .

The formula is used to find the ____________________ to estimate a population proportion.

A random sample of 25 observations is selected from a normally distributed population.The sample variance is 10.In the 95% confidence interval for the population variance,the upper limit is:

The ____________________ confidence limit of the confidence interval estimator of the population variance is .

The t-test for a population mean is ____________________,meaning that if the population is nonnormal,the results of the test and confidence interval are still valid as long as the nonnormality is not extreme.

The area to the right of a certain critical value on a chi-squared distribution is 0.025.For 5 degrees of freedom,the critical value is 11.143.

The statistic when the sampled population is normal is Student t-distributed with n degrees of freedom.

To test to see if the majority of the population exhibits a certain characteristic of interest,the alternative hypothesis of the test is H₁: p ____________________.

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

In testing a hypothesis about a population proportion p,the z test statistic measures how close the computed sample proportion has come to the hypothesized population parameter.

The test statistic used to test hypotheses about the population variance is given by χ2 = (n − 1)s2 / σ2,which is chi-squared distributed with n − 1 degrees of freedom when the population random variable is normally distributed with variance equal to σ2.

For statistical inference about the mean of a single population when the population standard deviation is unknown,the degrees for freedom for the t-distribution equal n − 1 because we lose one degree of freedom by using the:

A random sample of size 16 taken from a normally distributed population revealed a sample mean of 50 and a sample variance of 36.The upper limit of a 95% confidence interval for the population mean would equal:

Applicants' Grades The grades of a sample of 10 applicants,selected at random from a large population,are 71,86,75,63,92,70,81,59,80,and 90. ​ ​ -{Applicants' Grades Narrative} Construct a 90% confidence interval estimate for the population variance.

From a sample of 400 items,14 are found to be defective.The point estimate of the population proportion defective will be:

The ____________________ confidence limit of the confidence interval estimator of the population variance is .

The formula is used to find the ____________________ to estimate a population proportion.

A random sample of 25 observations is selected from a normally distributed population.The sample variance is 10.In the 95% confidence interval for the population variance,the upper limit is:

The ____________________ confidence limit of the confidence interval estimator of the population variance is . ​

The t-test for a population mean is ____________________,meaning that if the population is nonnormal,the results of the test and confidence interval are still valid as long as the nonnormality is not extreme.

The area to the right of a certain critical value on a chi-squared distribution is 0.025.For 5 degrees of freedom,the critical value is 11.143.

The statistic when the sampled population is normal is Student t-distributed with n degrees of freedom.

To test to see if the majority of the population exhibits a certain characteristic of interest,the alternative hypothesis of the test is H1: p ____________________.

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 test statistic used to test hypotheses about the population variance is given by χ² = (n − 1)s² / σ²,which is chi-squared distributed with n − 1 degrees of freedom when the population random variable is normally distributed with variance equal to σ².

Applicants' Grades The grades of a sample of 10 applicants,selected at random from a large population,are 71,86,75,63,92,70,81,59,80,and 90. -{Applicants' Grades Narrative} Construct a 90% confidence interval estimate for the population variance.

The ____________________ confidence limit of the confidence interval estimator of the population variance is .

To test to see if the majority of the population exhibits a certain characteristic of interest,the alternative hypothesis of the test is H₁: p ____________________.