Exam 8: Sampling Methods and the Central Limit Theorem

Bones Brothers & Associates prepare individual tax returns. Over prior years, Bones Brothers has maintained careful records regarding the time to prepare a return. The mean time to prepare a return is 90 minutes and the standard deviation of this distribution is 14 minutes. Suppose 100 returns from this year are selected and analyzed regarding the preparation time. What is the probability that the mean time for the sample of 100 returns is between 88 minutes and 92 minutes?

(Multiple Choice)

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Question 81

LongLast Inc. produces car batteries. The mean life of these batteries is 60 months. The distribution of the battery life closely follows the normal probability distribution with a standard deviation of eight months. As part of its testing program, LongLast tests a sample of 25 batteries. What is the standard error of the mean?

(Essay)

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Question 82

Bones Brothers & Associates prepare individual tax returns. Over prior years, Bones Brothers has maintained careful records regarding the time to prepare a return. The mean time to prepare a return is 90 minutes and the standard deviation of this distribution is 14 minutes. Suppose 100 returns from this year are selected and analyzed regarding the preparation time. What is the standard error of the mean?

(Multiple Choice)

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Question 83

When doing research, knowing the population mean and other population parameters is essential.

(True/False)

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Question 84

The mean of all possible sample means is equal to ____________.

(Multiple Choice)

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Question 85

LongLast Inc. produces car batteries. The mean life of these batteries is 60 months. The distribution of the battery life closely follows the normal probability distribution with a standard deviation of eight months. As a part of its testing program, LongLast tests a sample of 25 batteries. What proportion of the samples will have a mean useful life between 58 and 62 months?

(Essay)

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Question 86

How is the central limit theorem helpful when computing probabilities?

(Essay)

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Question 87

The size of the sampling error is ________.

(Multiple Choice)

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Question 88

A population consists of 14 values. How many samples of size five are possible?

(Essay)

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Question 89

The following data was collected from a simple random sample of a population of college freshmen. It represents their ages on the first day of the fall semester. 17 21 19 18 18 19 The point estimates of the population mean and standard deviation are:

(Multiple Choice)

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Question 90

For a sampling distribution of the means, about ________% of the means would be between ±1.96 standard deviations.

(Short Answer)

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Question 91

The central limit theorem states that if the sample size, n, is sufficiently large, the sampling distribution of the means will be approximately normal, even when the population is skewed or uniform.

(True/False)

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Question 92

The American Auto Association reports that the mean price per gallon of regular gasoline is $3.10, with a population standard deviation of $0.20. Assume a random sample of 16 gasoline stations is selected and their mean cost for regular gasoline is computed. What is the standard error of the mean in this experiment?

(Essay)

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Question 93

A characteristic of a population is called a ______________.

(Short Answer)

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Question 94

In stratified random sampling, a population is divided into strata using naturally occurring geographic or other boundaries. Then, strata are randomly selected and a random sample is collected from each strata.

(True/False)

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Question 95

To study the population of consumer perceptions of new technology, sampling of the population is preferred over surveying the population because _________.

(Multiple Choice)

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Question 96

Auditors may select every 20^th file starting with the 5^th file in the top drawer. Then, file numbers 25, 45, 65, 85, . . . are selected. This type of sampling is called ___________.

(Short Answer)

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Question 97

The Intelligence Quotient (IQ) test scores for adults are normally distributed with a mean of 100 and a standard deviation of 15. What is the probability we could select a sample of 50 adults and find that the mean of this sample is between 98 and 103?

(Multiple Choice)

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Question 98

If every k^th item in the population sequence is selected, you should use the __________________ sampling method.

(Short Answer)

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Question 99

For a sampling distribution of the means, _______% of the means would be between ±2.58 standard deviations.

(Short Answer)

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Question 100

Showing 81 - 100 of 117

When doing research, knowing the population mean and other population parameters is essential.

The mean of all possible sample means is equal to ____________.

How is the central limit theorem helpful when computing probabilities?

The size of the sampling error is ________.

A population consists of 14 values. How many samples of size five are possible?

The following data was collected from a simple random sample of a population of college freshmen. It represents their ages on the first day of the fall semester. 17 21 19 18 18 19 The point estimates of the population mean and standard deviation are:

For a sampling distribution of the means, about ________% of the means would be between ±1.96 standard deviations.

The central limit theorem states that if the sample size, n, is sufficiently large, the sampling distribution of the means will be approximately normal, even when the population is skewed or uniform.

A characteristic of a population is called a ______________.

In stratified random sampling, a population is divided into strata using naturally occurring geographic or other boundaries. Then, strata are randomly selected and a random sample is collected from each strata.

To study the population of consumer perceptions of new technology, sampling of the population is preferred over surveying the population because _________.

Auditors may select every 20^th file starting with the 5^th file in the top drawer. Then, file numbers 25, 45, 65, 85, . . . are selected. This type of sampling is called ___________.

The Intelligence Quotient (IQ) test scores for adults are normally distributed with a mean of 100 and a standard deviation of 15. What is the probability we could select a sample of 50 adults and find that the mean of this sample is between 98 and 103?

If every k^th item in the population sequence is selected, you should use the __________________ sampling method.

For a sampling distribution of the means, _______% of the means would be between ±2.58 standard deviations.

What Is Statistics

Describing Data: Frequency Tables, Frequency Distributions, and Graphic Presentation

Describing Data: Numerical Measures

Describing Data: Displaying and Exploring Data

A Survey of Probability Concepts

Discrete Probability Distributions

Continuous Probability Distributions

Estimation and Confidence Intervals

One-Sample Tests of Hypothesis

Two-Sample Tests of Hypothesis

Analysis of Variance

Correlation and Linear Regression

Multiple Regression Analysis

Nonparametric Methods: Nominal Level Hypothesis Tests

Nonparametric Methods: Analysis of Ordinal Data

Index Numbers

Time Series and Forecasting

Statistical Process Control and Quality Management

An Introduction to Decision Theory

Filters

Exam 8: Sampling Methods and the Central Limit Theorem

When doing research, knowing the population mean and other population parameters is essential.

The mean of all possible sample means is equal to ____________.

How is the central limit theorem helpful when computing probabilities?

The size of the sampling error is ________.

A population consists of 14 values. How many samples of size five are possible?

The following data was collected from a simple random sample of a population of college freshmen. It represents their ages on the first day of the fall semester. 17 21 19 18 18 19 The point estimates of the population mean and standard deviation are:

For a sampling distribution of the means, about ________% of the means would be between ±1.96 standard deviations.

The central limit theorem states that if the sample size, n, is sufficiently large, the sampling distribution of the means will be approximately normal, even when the population is skewed or uniform.

A characteristic of a population is called a ______________.

In stratified random sampling, a population is divided into strata using naturally occurring geographic or other boundaries. Then, strata are randomly selected and a random sample is collected from each strata.

To study the population of consumer perceptions of new technology, sampling of the population is preferred over surveying the population because _________.

Auditors may select every 20th file starting with the 5th file in the top drawer. Then, file numbers 25, 45, 65, 85, . . . are selected. This type of sampling is called ___________.

The Intelligence Quotient (IQ) test scores for adults are normally distributed with a mean of 100 and a standard deviation of 15. What is the probability we could select a sample of 50 adults and find that the mean of this sample is between 98 and 103?

If every kth item in the population sequence is selected, you should use the __________________ sampling method.

For a sampling distribution of the means, _______% of the means would be between ±2.58 standard deviations.

What Is Statistics

Describing Data: Frequency Tables, Frequency Distributions, and Graphic Presentation

Describing Data: Numerical Measures

Describing Data: Displaying and Exploring Data

A Survey of Probability Concepts

Discrete Probability Distributions

Continuous Probability Distributions

Estimation and Confidence Intervals

One-Sample Tests of Hypothesis

Two-Sample Tests of Hypothesis

Analysis of Variance

Correlation and Linear Regression

Multiple Regression Analysis

Nonparametric Methods: Nominal Level Hypothesis Tests

Nonparametric Methods: Analysis of Ordinal Data

Index Numbers

Time Series and Forecasting

Statistical Process Control and Quality Management

An Introduction to Decision Theory

Filters

Auditors may select every 20^th file starting with the 5^th file in the top drawer. Then, file numbers 25, 45, 65, 85, . . . are selected. This type of sampling is called ___________.

If every k^th item in the population sequence is selected, you should use the __________________ sampling method.