Question 1

The density function of the standard normal distribution has a wider dispersion than the Student's t distribution.

Accepted Answer

A) True 
 B)False

Question 2

All other things being equal,the larger the sample size,the narrower the interval estimates that reflect the uncertainty about a parameter's true value.

Accepted Answer

A) True 
 B)False

Question 3

The amount of material used in making a custom sail for a sailboat is normally distributed.For a random sample of 15 sails,you find that the mean amount of material is 912 square feet,with a standard deviation of 64 square feet.Develop a 99% confidence interval for the population mean amount of material used in a custom sail.

Accepted Answer

The answer of The amount of material used in making...

Question 4

A student records the time (in minutes)it takes to commute to school for seven days.Those results are: 21,15,13,16,10,13,and 18.Assuming the population is normally distributed,develop a 95% confidence interval for the population mean.

Accepted Answer

The answer of A student records the time (in minutes)it...

Question 5

If a sample of size 30 is selected,the value of A for the probability P(t ≥A)= 0.01 is:

Accepted Answer

A) 2.247 
B) 2.045 
C) 2.462 
D) 2.750

Question 6

If Var (  1)= σ2 and Var (  2)= 2σ2,then the relative efficiency of  
1 with respect to  
2 is equal to 0.5.

Accepted Answer

A) True 
 B)False

Question 7

The lower limit of the 90% confidence interval for the population proportion P,given that n = 400;and  
= 0.10 is 0.1247.

Accepted Answer

A) True 
 B)False

Question 8

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION:
A clinic offers a weight-reduction program.A review of its records revealed the following weight losses,in pounds,for a random sample of 10 of its clients at the conclusion of the program: 20,15,21,28,22,19,9,14,18,and 23.
-To calculate a required sample size to estimate a population proportion,given a desired confidence interval and margin of error,the sample proportion is required but often unknown before the sample is collected.How is this predicament resolved?

Accepted Answer

The answer of THE NEXT QUESTIONS ARE BASED ON THE...

Question 9

For a population that is normally distributed with a very large population size compared to the sample size,the variance of the sample mean  is given by:

Accepted Answer

A) σ /  
B) σ2 /  
C) σ / n 
D) σ2 / n

Question 10

The dollar value of orders placed through a particular store catalog is found to be normally distributed with a standard deviation of $21.58.A sample of 30 orders averaged $81.25.What is the 90% confidence interval around this sample mean?

Accepted Answer

A) $81.25 ± $21.58 
B) $81.25 ± $10.79 
C) $81.25 ± $12.15 
D) $81.25 ± $6.48

Question 11

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION:
The data shown below specify how much a sample of 20 executives paid in federal income taxes,as a percentage of gross income,are reproduced below.
  
Assume that the standard deviation for the underlying population is equal to 4.0.
-Give a careful verbal interpretation of the 99% confidence interval for the population mean.

Accepted Answer

The answer of THE NEXT QUESTIONS ARE BASED ON THE...

Exam 7: Estimation: Single Population

The density function of the standard normal distribution has a wider dispersion than the Student's t distribution.

All other things being equal,the larger the sample size,the narrower the interval estimates that reflect the uncertainty about a parameter's true value.

A student records the time (in minutes)it takes to commute to school for seven days.Those results are: 21,15,13,16,10,13,and 18.Assuming the population is normally distributed,develop a 95% confidence interval for the population mean.

If a sample of size 30 is selected,the value of A for the probability P(t ≥A) = 0.01 is:

If Var ( ₁)= σ² and Var ( ₂)= 2σ²,then the relative efficiency of ₁ with respect to ₂ is equal to 0.5.

The lower limit of the 90% confidence interval for the population proportion P,given that n = 400;and = 0.10 is 0.1247.

For a population that is normally distributed with a very large population size compared to the sample size,the variance of the sample mean is given by:

The dollar value of orders placed through a particular store catalog is found to be normally distributed with a standard deviation of $21.58.A sample of 30 orders averaged $81.25.What is the 90% confidence interval around this sample mean?

Exam 7: Estimation: Single Population

The density function of the standard normal distribution has a wider dispersion than the Student's t distribution.

All other things being equal,the larger the sample size,the narrower the interval estimates that reflect the uncertainty about a parameter's true value.

A student records the time (in minutes)it takes to commute to school for seven days.Those results are: 21,15,13,16,10,13,and 18.Assuming the population is normally distributed,develop a 95% confidence interval for the population mean.

If a sample of size 30 is selected,the value of A for the probability P(t ≥A) = 0.01 is:

If Var ( 1)= σ2 and Var ( 2)= 2σ2,then the relative efficiency of 1 with respect to 2 is equal to 0.5.

The lower limit of the 90% confidence interval for the population proportion P,given that n = 400;and = 0.10 is 0.1247.

For a population that is normally distributed with a very large population size compared to the sample size,the variance of the sample mean is given by:

The dollar value of orders placed through a particular store catalog is found to be normally distributed with a standard deviation of $21.58.A sample of 30 orders averaged $81.25.What is the 90% confidence interval around this sample mean?

If Var ( ₁)= σ² and Var ( ₂)= 2σ²,then the relative efficiency of ₁ with respect to ₂ is equal to 0.5.