Question 1

When the level of confidence increases, the confidence interval _____.

Accepted Answer

A)  stays the same 
B)  becomes wider 
C)  becomes narrower 
D)  cannot be determined from the information given 
A)  stays the same 
B)  becomes wider 
C)  becomes narrower 
D)  cannot be determined from the information given

Question 2

A 95% confidence interval for a population mean is determined to be 100 to 120. If the confidence coefficient is reduced to .90, the interval for μ _____.

Accepted Answer

A)  becomes narrower 
B)  becomes wider 
C)  does not change 
D)  becomes .1 
A)  becomes narrower 
B)  becomes wider 
C)  does not change 
D)  becomes .1

Question 3

The probability that the interval estimation procedure will generate an interval that contains the actual value of the population parameter being estimated is the _____.

Accepted Answer

A)  level of significance 
B)  confidence level 
C)  confidence coefficient 
D)  error factor 
A)  level of significance 
B)  confidence level 
C)  confidence coefficient 
D)  error factor

Question 4

The expression used to compute an interval estimate of μ may depend on any of the following factors EXCEPT _____.

Accepted Answer

A)  the sample size 
B)  whether the population standard deviation is known 
C)  whether the population has an approximately normal distribution 
D)  whether there is sampling error 
A)  the sample size 
B)  whether the population standard deviation is known 
C)  whether the population has an approximately normal distribution 
D)  whether there is sampling error

Question 5

An estimate of a population parameter that provides an interval believed to contain the value of the parameter is known as the _____.

Accepted Answer

A)  confidence level 
B)  interval estimate 
C)  parameter value 
D)  population estimate 
A)  confidence level 
B)  interval estimate 
C)  parameter value 
D)  population estimate

Question 6

If we want to provide a 95% confidence interval for the mean of a population, the confidence coefficient is _____.

Accepted Answer

A)  .485 
B)  1.96 
C)  .95 
D)  1.645 
A)  .485 
B)  1.96 
C)  .95 
D)  1.645

Question 7

If the margin of error in an interval estimate of ? is 4.6, the interval estimate equals _____.

Accepted Answer

A)  $\bar { x } \pm 2.3$ 
B)  $\bar { x } \pm 4.6$ 
C)  $\bar { x } \pm 4.508$ 
D)  $\bar { x } \pm 6.9$ 
A)  $\bar { x } \pm 2.3$ 
B)  $\bar { x } \pm 4.6$ 
C)  $\bar { x } \pm 4.508$ 
D)  $\bar { x } \pm 6.9$

Question 8

A newspaper wants to estimate the proportion of Americans who will vote for Candidate A. A random sample of 1000 voters is selected. Of the 1000 respondents, 526 say that they will vote for Candidate A. Which Excel function would be used to construct a confidence interval estimate?

Accepted Answer

A)  NORM.S.INV 
B)  NORM.INV 
C)  T.INV 
D)  INT 
A)  NORM.S.INV 
B)  NORM.INV 
C)  T.INV 
D)  INT

Question 9

A random sample of 25 statistics examinations was selected. The average score in the sample was 76 with a variance of 144. Assuming the scores are normally distributed, the 99% confidence interval for the population average examination score is _____.

Accepted Answer

A)  70.02 to 81.98 
B)  69.82 to 82.18 
C)  70.06 to 81.94 
D)  69.29 to 82.71 
A)  70.02 to 81.98 
B)  69.82 to 82.18 
C)  70.06 to 81.94 
D)  69.29 to 82.71

Question 10

Whenever the population standard deviation is unknown, which distribution is used in developing an interval estimate for a population mean?

Accepted Answer

A)  standard distribution 
B)  z distribution 
C)  binomial distribution 
D)  t distribution 
A)  standard distribution 
B)  z distribution 
C)  binomial distribution 
D)  t distribution

Question 11

A manufacturer wants to estimate the proportion of defective items that are produced by a certain machine. A random sample of 50 items is selected. Which Excel function would NOT be appropriate to construct a confidence interval estimate?

Accepted Answer

A)  NORM.S.INV 
B)  COUNTIF 
C)  STDEV 
D)  All of these answers are correct. 
A)  NORM.S.INV 
B)  COUNTIF 
C)  STDEV 
D)  All of these answers are correct.

Question 12

In determining the sample size necessary to estimate a population proportion, which of the following is NOT needed?

Accepted Answer

A)  the maximum margin of error that can be tolerated 
B)  the confidence level required 
C)  a preliminary estimate of the true population proportion p 
D)  the mean of the population 
A)  the maximum margin of error that can be tolerated 
B)  the confidence level required 
C)  a preliminary estimate of the true population proportion p 
D)  the mean of the population

Question 13

In determining the sample size necessary to estimate a population proportion, which of the following is NOT needed?

Accepted Answer

A)  the maximum margin of error that can be tolerated 
B)  the confidence level required 
C)  a preliminary estimate of the true population proportion p 
D)  the mean of the population 
A)  the maximum margin of error that can be tolerated 
B)  the confidence level required 
C)  a preliminary estimate of the true population proportion p 
D)  the mean of the population

Question 14

Below you are given ages that were obtained by taking a random sample of nine undergraduate students.
19
22
23
19
21
22
19
23
21
Use Excel to determine an interval estimate for the mean of the population at a 99% confidence level. Interpret your results.

Accepted Answer

​ @#IMG-DLM& Interpretation of Interval

Question 15

A random sample of 25 employees of a local company has been measured. A 95% confidence interval estimate for the mean systolic blood pressure for all company employees is 123 to 139. Which of the following statements is valid?

Accepted Answer

A)  95% of the sample of employees has a systolic blood pressure between 123 and 139. 
B)  If the sampling procedure were repeated many times, 95% of the resulting confidence intervals would contain the population mean systolic blood pressure. 
C)  95% of the population of employees has a systolic blood pressure between 123 and 139. 
D)  If the sampling procedure were repeated many times, 95% of the sample means would be between 123 and 139. 
A)  95% of the sample of employees has a systolic blood pressure between 123 and 139. 
B)  If the sampling procedure were repeated many times, 95% of the resulting confidence intervals would contain the population mean systolic blood pressure. 
C)  95% of the population of employees has a systolic blood pressure between 123 and 139. 
D)  If the sampling procedure were repeated many times, 95% of the sample means would be between 123 and 139.

When the level of confidence increases, the confidence interval _____.

A 95% confidence interval for a population mean is determined to be 100 to 120. If the confidence coefficient is reduced to .90, the interval for μ _____.

The probability that the interval estimation procedure will generate an interval that contains the actual value of the population parameter being estimated is the _____.

The expression used to compute an interval estimate of μ may depend on any of the following factors EXCEPT _____.

An estimate of a population parameter that provides an interval believed to contain the value of the parameter is known as the _____.

If we want to provide a 95% confidence interval for the mean of a population, the confidence coefficient is _____.

If the margin of error in an interval estimate of ? is 4.6, the interval estimate equals _____.

A newspaper wants to estimate the proportion of Americans who will vote for Candidate A. A random sample of 1000 voters is selected. Of the 1000 respondents, 526 say that they will vote for Candidate A. Which Excel function would be used to construct a confidence interval estimate?

A random sample of 25 statistics examinations was selected. The average score in the sample was 76 with a variance of 144. Assuming the scores are normally distributed, the 99% confidence interval for the population average examination score is _____.

Whenever the population standard deviation is unknown, which distribution is used in developing an interval estimate for a population mean?

A manufacturer wants to estimate the proportion of defective items that are produced by a certain machine. A random sample of 50 items is selected. Which Excel function would NOT be appropriate to construct a confidence interval estimate?

In determining the sample size necessary to estimate a population proportion, which of the following is NOT needed?

In determining the sample size necessary to estimate a population proportion, which of the following is NOT needed?

Below you are given ages that were obtained by taking a random sample of nine undergraduate students. 19 22 23 19 21 22 19 23 21 Use Excel to determine an interval estimate for the mean of the population at a 99% confidence level. Interpret your results.

A random sample of 25 employees of a local company has been measured. A 95% confidence interval estimate for the mean systolic blood pressure for all company employees is 123 to 139. Which of the following statements is valid?

Data and Statistics

Descriptive Statistics: Tabular and Graphical Displays

Descriptive Statistics: Numerical Measures

Introduction to Probability

Discrete Probability Distributions

Continuous Probability Distributions

Sampling and Sampling Distributions

Hypothesis Tests

Inference About Means and Proportions With Two Populations

Inferences About Population Variances

Tests of Goodness of Fit, Independence, and Multiple Proportions

Experimental Design and Analysis of Variance

Simple Linear Regression

Multiple Regression

Regression Analysis: Model Building

Time Series Analysis and Forecasting

Nonparametric Methods

Statistical Methods for Quality Control

Decision Analysis

Sample Survey

Filters

Exam 8: Interval Estimation

When the level of confidence increases, the confidence interval _____.

A 95% confidence interval for a population mean is determined to be 100 to 120. If the confidence coefficient is reduced to .90, the interval for μ _____.

The probability that the interval estimation procedure will generate an interval that contains the actual value of the population parameter being estimated is the _____.

The expression used to compute an interval estimate of μ may depend on any of the following factors EXCEPT _____.

An estimate of a population parameter that provides an interval believed to contain the value of the parameter is known as the _____.

If we want to provide a 95% confidence interval for the mean of a population, the confidence coefficient is _____.

If the margin of error in an interval estimate of ? is 4.6, the interval estimate equals _____.

A newspaper wants to estimate the proportion of Americans who will vote for Candidate A. A random sample of 1000 voters is selected. Of the 1000 respondents, 526 say that they will vote for Candidate A. Which Excel function would be used to construct a confidence interval estimate?

A random sample of 25 statistics examinations was selected. The average score in the sample was 76 with a variance of 144. Assuming the scores are normally distributed, the 99% confidence interval for the population average examination score is _____.

Whenever the population standard deviation is unknown, which distribution is used in developing an interval estimate for a population mean?

A manufacturer wants to estimate the proportion of defective items that are produced by a certain machine. A random sample of 50 items is selected. Which Excel function would NOT be appropriate to construct a confidence interval estimate?

In determining the sample size necessary to estimate a population proportion, which of the following is NOT needed?

In determining the sample size necessary to estimate a population proportion, which of the following is NOT needed?

Below you are given ages that were obtained by taking a random sample of nine undergraduate students. 19 22 23 19 21 22 19 23 21 Use Excel to determine an interval estimate for the mean of the population at a 99% confidence level. Interpret your results.

A random sample of 25 employees of a local company has been measured. A 95% confidence interval estimate for the mean systolic blood pressure for all company employees is 123 to 139. Which of the following statements is valid?

Data and Statistics

Descriptive Statistics: Tabular and Graphical Displays

Descriptive Statistics: Numerical Measures

Introduction to Probability

Discrete Probability Distributions

Continuous Probability Distributions

Sampling and Sampling Distributions

Hypothesis Tests

Inference About Means and Proportions With Two Populations

Inferences About Population Variances

Tests of Goodness of Fit, Independence, and Multiple Proportions

Experimental Design and Analysis of Variance

Simple Linear Regression

Multiple Regression

Regression Analysis: Model Building

Time Series Analysis and Forecasting

Nonparametric Methods

Statistical Methods for Quality Control

Decision Analysis

Sample Survey

Filters