Question 1

A confidence interval will allow us to say with complete certainty that our sample result will actually include the population mean.

Accepted Answer

A) True 
 B)False  False

Question 2

A cost accountant wishes to establish the average amount, $\mu$ ,spent by executives per day on travel and lodging.Then a comparison,between the average and the amount turned in to be reimbursed,will be made and unreasonably high or low expense amounts audited.A random sample of 50 executive expense receipts is taken.The average in the sample was $208.From a similar survey the standard deviation of the amounts is approximately $\text { σ }$ = $29.The accountant prepares a 90-percent confidence level for $\mu$ .What is the confidence interval?
____________________ to ____________________

Accepted Answer

$201.25; $214.75

Question 3

A medical records manager would like to review hospital records in order to determine the average hospital stay for surgery patients during the past year.What sample size must be taken in order to be 95% confident that the estimate is within 1 day of the true mean? She has past studies,which indicate that $\text { σ }$
 is 20.25 days.

Accepted Answer

1576

Question 4

A filling machine is designed to fill soda bottles with 16 ounces of soda.The distribution for the weight of the bottles is normal.Twenty bottles are selected and weighed.The sample mean is 15.3 ounces and sample standard deviation is 1.5 ounces.Develop a 90% confidence interval for this sample.What can we conclude about this filling process?

Accepted Answer

14.72 ounces,15.88 ounces.Sinc

Question 5

A survey of 9512 residents of the 3rd congressional district of Colorado showed that 6134 favored cutting military spending in order to help balance the federal budget.Construct a 90% confidence interval estimate for the proportion of all residents in the 3rd district who favor cutting military spending to help balance the federal budget.
____________________ to ____________________

Accepted Answer

The answer of A survey of 9512 residents of the...

Question 6

To use the normal approximation to determine a confidence interval to estimate a population proportion,np and n(1-p)must both be greater than or equal to 5.

Accepted Answer

A) True 
 B)False

Question 7

A confidence interval is an estimate for which there is a specified degree of certainty that the population parameter will be in the interval.

Accepted Answer

A) True 
 B)False

Question 8

A random sample of 10 university students was surveyed to determine the amount of time spent weekly using a personal computer.The times are: 13,14,5,6,8,10,7,12,15,and 3.If the times are normally distributed with a standard deviation of 5.2 hours,estimate with 90% confidence the mean weekly time spent using a personal computer by all university students.
____________________ to ____________________

Accepted Answer

The answer of A random sample of 10 university students...

Question 9

To use the t distribution for a small sample size when deriving a confidence interval requires that the population be normally distributed.

Accepted Answer

A) True 
 B)False

Question 10

The t-distribution approaches the normal distribution as the:

Accepted Answer

A)  degrees of freedom increase. 
B)  degrees of freedom decrease. 
C)  sample size decreases. 
D)  population size increases. 
A)  degrees of freedom increase. 
B)  degrees of freedom decrease. 
C)  sample size decreases. 
D)  population size increases.

Question 11

A 95% confidence interval means that there is a 95% probability that the interval will include the true population mean.

Accepted Answer

A) True 
 B)False

Question 12

If a sample has 16 observations and a 95% confidence estimate for $\mu$ is needed,the appropriate t-score is 1.746.

Accepted Answer

A) True 
 B)False

Question 13

In a survey of 600 senior business executives by Business Week magazine,56% indicated that they felt that even if merit and abilities are equal,people with MBAs often get promoted faster than people without the degree.Prepare a 92% confidence interval estimate for the population proportion.
____________________ to ____________________

Accepted Answer

The answer of In a survey of 600 senior business...

Question 14

Determine the limits of the 68.26% confidence interval for $\mu$ ,given that n = 64; $\bar { x }$ = 118; and $\text { σ }$ = 8.
____________________ to ____________________

Accepted Answer

The answer of Determine the limits of the 68.26% confidence...

Question 15

The security department of a state university is planning its budget for the next year.In estimating the man-hours for security during university sponsored music concerts,the average length of music concerts is needed.A random sample from thirty-six security departments at universities was taken and the sample mean length of concerts was 160 minutes.Suppose the population standard deviation is 45 minutes.A 95 percent confidence interval for the true mean duration of music concerts is:

Accepted Answer

A)  157.55 to 162.45. 
B)  147.63 to 172.37. 
C)  71.8 to 248.2. 
D)  145.3 to 174.7. 
E)  1601.96(45 / 36). 
A)  157.55 to 162.45. 
B)  147.63 to 172.37. 
C)  71.8 to 248.2. 
D)  145.3 to 174.7. 
E)  1601.96(45 / 36).

Question 16

An auditor wishes to take a sample to verify the accounts receivable balances for a very large corporation.From past history,he knows that $\text { σ }$
 is $102.49.What sample size must be taken to be 99% confident that the estimate will be within $5 of the true mean account balance?

Accepted Answer

The answer of An auditor wishes to take a sample...

Question 17

A sample of 32 orders for a home shopping channel has an average of $78.25.The standard deviation for all orders (the population)is $37.50.A 90% confidence interval around this sample mean would be:

Accepted Answer

A) $\$ 78.25 \pm \$ 37.50$ 
B) $\$ 78.25 \pm \$ 10.87$ 
C) $\$ 78.25 \pm \$ 6.63$ 
D) $\$ 37.50 \pm \$ 6.63$ 
E)  $\$ 37.50 \pm \$ 1.64$ 
A) $\$ 78.25 \pm \$ 37.50$ 
B) $\$ 78.25 \pm \$ 10.87$ 
C) $\$ 78.25 \pm \$ 6.63$ 
D) $\$ 37.50 \pm \$ 6.63$ 
E)  $\$ 37.50 \pm \$ 1.64$

Question 18

There are 300 students enrolled in Business Statistics.Historically,exam scores are normally distributed with a standard deviation of 30.9.Your instructor randomly selected a sample of 30 examinations and finds a mean of 74.2.Determine a 90% confidence interval for the mean score for all students taking the course.
____________________ to ____________________

Accepted Answer

The answer of There are 300 students enrolled in Business...

Question 19

The appropriate procedure for constructing an interval estimate for the population mean depends largely on whether the population standard deviation $\text { ? }$
 is known.

Accepted Answer

A) True 
 B)False

Question 20

The finite population correction factor will lead to a wider confidence interval than if an infinite population had been assumed.

Accepted Answer

A) True 
 B)False

A confidence interval will allow us to say with complete certainty that our sample result will actually include the population mean.

To use the normal approximation to determine a confidence interval to estimate a population proportion,np and n(1-p)must both be greater than or equal to 5.

A confidence interval is an estimate for which there is a specified degree of certainty that the population parameter will be in the interval.

To use the t distribution for a small sample size when deriving a confidence interval requires that the population be normally distributed.

The t-distribution approaches the normal distribution as the:

A 95% confidence interval means that there is a 95% probability that the interval will include the true population mean.

If a sample has 16 observations and a 95% confidence estimate for $\mu$ is needed,the appropriate t-score is 1.746.

In a survey of 600 senior business executives by Business Week magazine,56% indicated that they felt that even if merit and abilities are equal,people with MBAs often get promoted faster than people without the degree.Prepare a 92% confidence interval estimate for the population proportion. to

Determine the limits of the 68.26% confidence interval for $\mu$ ,given that n = 64; $\bar { x }$ = 118; and $\text { σ }$ = 8. to

An auditor wishes to take a sample to verify the accounts receivable balances for a very large corporation.From past history,he knows that $\text { σ }$ is $102.49.What sample size must be taken to be 99% confident that the estimate will be within $5 of the true mean account balance?

A sample of 32 orders for a home shopping channel has an average of $78.25.The standard deviation for all orders (the population)is $37.50.A 90% confidence interval around this sample mean would be:

The appropriate procedure for constructing an interval estimate for the population mean depends largely on whether the population standard deviation $\text { ? }$ is known.

The finite population correction factor will lead to a wider confidence interval than if an infinite population had been assumed.

A Preview of Business Statistics

Visual Description of Data

Statistical Description of Data

Data Collection and Sampling Methods

Probability: Review of Basic Concepts

Discrete Probability Distributions

Continuous Probability Distributions

Sampling Distributions

Hypothesis Tests Involving a Sample Mean or Proportion

Hypothesis Tests Involving Two Sample Means

Analysis of Variance Tests

Chi-Square Applications

Nonparametric Methods

Simple Linear Regression and Correlation

Multiple Regression and Correlation

Model Building

Models for Time Series and Forecasting

Decision Theory

Total Quality Management

Filters

Exam 9: Estimation From Sample Data

A confidence interval will allow us to say with complete certainty that our sample result will actually include the population mean.

To use the normal approximation to determine a confidence interval to estimate a population proportion,np and n(1-p)must both be greater than or equal to 5.

A confidence interval is an estimate for which there is a specified degree of certainty that the population parameter will be in the interval.

To use the t distribution for a small sample size when deriving a confidence interval requires that the population be normally distributed.

The t-distribution approaches the normal distribution as the:

A 95% confidence interval means that there is a 95% probability that the interval will include the true population mean.

If a sample has 16 observations and a 95% confidence estimate for μ\muμ is needed,the appropriate t-score is 1.746.

Determine the limits of the 68.26% confidence interval for μ\muμ ,given that n = 64; xˉ\bar { x }xˉ = 118; and σ \text { σ } σ = 8. ____________________ to ____________________

An auditor wishes to take a sample to verify the accounts receivable balances for a very large corporation.From past history,he knows that σ \text { σ } σ is $102.49.What sample size must be taken to be 99% confident that the estimate will be within $5 of the true mean account balance?

A sample of 32 orders for a home shopping channel has an average of $78.25.The standard deviation for all orders (the population)is $37.50.A 90% confidence interval around this sample mean would be:

The appropriate procedure for constructing an interval estimate for the population mean depends largely on whether the population standard deviation ? \text { ? } ? is known.

The finite population correction factor will lead to a wider confidence interval than if an infinite population had been assumed.

A Preview of Business Statistics

Visual Description of Data

Statistical Description of Data

Data Collection and Sampling Methods

Probability: Review of Basic Concepts

Discrete Probability Distributions

Continuous Probability Distributions

Sampling Distributions

Hypothesis Tests Involving a Sample Mean or Proportion

Hypothesis Tests Involving Two Sample Means

Analysis of Variance Tests

Chi-Square Applications

Nonparametric Methods

Simple Linear Regression and Correlation

Multiple Regression and Correlation

Model Building

Models for Time Series and Forecasting

Decision Theory

Total Quality Management

Filters

If a sample has 16 observations and a 95% confidence estimate for $\mu$ is needed,the appropriate t-score is 1.746.

Determine the limits of the 68.26% confidence interval for $\mu$ ,given that n = 64; $\bar { x }$ = 118; and $\text { σ }$ = 8. to

An auditor wishes to take a sample to verify the accounts receivable balances for a very large corporation.From past history,he knows that $\text { σ }$ is $102.49.What sample size must be taken to be 99% confident that the estimate will be within $5 of the true mean account balance?

The appropriate procedure for constructing an interval estimate for the population mean depends largely on whether the population standard deviation $\text { ? }$ is known.