Question 1

During a natural gas shortage, a gas company randomly sampled residential gas meters in order to monitor daily gas consumption. On a particular day, a sample of 100 meters showed a sample mean of 250 cubic feet and a sample standard deviation of 50 cubic feet. Provide a 90% confidence interval estimate of the mean gas consumption for the population.

Accepted Answer

The answer of During a natural gas shortage, a gas...

Question 2

In selecting the sample size to estimate the population proportion p, if we have no knowledge of even the approximate values of the sample proportion $\tilde { p }$ , we:

Accepted Answer

A) take another sample and estimate. 
B) take two more samples and find the average of their. 
C) let= 0.50. 
D) let= 0.95.

Question 3

The test statistic used to test hypotheses about the population variance has a(n) ____________________ distribution with ____________________ degrees of freedom.

Accepted Answer

The answer of The test statistic used to test hypotheses...

Question 4

The formula $\left( \frac { z _ { \alpha / 2 } \sqrt { \tilde{ p } ( 1 - \tilde { p } ) } } { B } \right) ^ { 2 }$ is used to find the sample size needed to estimate a population proportion. In this formula, B represents the ____________________ on the error of estimation.

Accepted Answer

The answer of The formula \(\left( \frac { z _...

Question 5

NARRBEGIN: New Mousetrap
New Mousetrap
After a financial analysis, the general manager of a large company decided that if more than 8% of potential buyers of a new mousetrap purchase that product, the company would show a profit. In a preliminary survey of 500 potential buyers, 56 people say that they will buy the mousetrap.NARREND
-{New Mousetrap Narrative} Is there sufficient evidence at the 5% significance level that the mousetrap will produce a profit?

Accepted Answer

The answer of NARRBEGIN: New Mousetrap
New Mousetrap
After a financial analysis,...

Question 6

The statistic $( \bar { x } - \mu ) / ( s / \sqrt { n } )$ when the sampled population is normal is Student t-distributed with n degrees of freedom.

Accepted Answer

A) True 
 B)False

Question 7

Which of the following is not an example illustrating the use of variance?

Accepted Answer

A) As a measure of risk. 
B) As a judge of consistency. 
C) To search for and reduce variability in a process. 
D) All of these choices are true.

Question 8

Which of the following would be an appropriate null hypothesis?

Accepted Answer

A) The population proportion is equal to 0.60. 
B) The sample proportion is equal to 0.60. 
C) The population proportion is not equal to 0.60. 
D) All of these choices are true.

Question 9

NARRBEGIN: Concert Tickets Concert Tickets A simple random sample of 100 concert tickets was drawn from a normal population. The mean and standard deviation of the sample were $120 and $25, respectively.NARREND -{Concert Tickets Narrative} Test the hypothesis H₀: $\mu$= 125 vs. H₁: $\mu$$\neq$125 at the 10% significance level.

Accepted Answer

The answer of NARRBEGIN: Concert Tickets
Concert Tickets
A simple random sample...

Exam 12: Inference About a Population

In selecting the sample size to estimate the population proportion p, if we have no knowledge of even the approximate values of the sample proportion $\tilde { p }$ , we:

The test statistic used to test hypotheses about the population variance has a(n) distribution with degrees of freedom.

The formula $\left( \frac { z _ { \alpha / 2 } \sqrt { \tilde{ p } ( 1 - \tilde { p } ) } } { B } \right) ^ { 2 }$ is used to find the sample size needed to estimate a population proportion. In this formula, B represents the ____________________ on the error of estimation.

The statistic $( \bar { x } - \mu ) / ( s / \sqrt { n } )$ when the sampled population is normal is Student t-distributed with n degrees of freedom.

Which of the following is not an example illustrating the use of variance?

Which of the following would be an appropriate null hypothesis?

Exam 12: Inference About a Population

In selecting the sample size to estimate the population proportion p, if we have no knowledge of even the approximate values of the sample proportion p~\tilde { p }p~​ , we:

The test statistic used to test hypotheses about the population variance has a(n) ____________________ distribution with ____________________ degrees of freedom.

The statistic (xˉ−μ)/(s/n)( \bar { x } - \mu ) / ( s / \sqrt { n } )(xˉ−μ)/(s/n​) when the sampled population is normal is Student t-distributed with n degrees of freedom.

Which of the following is not an example illustrating the use of variance?

Which of the following would be an appropriate null hypothesis?

In selecting the sample size to estimate the population proportion p, if we have no knowledge of even the approximate values of the sample proportion $\tilde { p }$ , we:

The test statistic used to test hypotheses about the population variance has a(n) distribution with degrees of freedom.

The statistic $( \bar { x } - \mu ) / ( s / \sqrt { n } )$ when the sampled population is normal is Student t-distributed with n degrees of freedom.