Question 1

Packages of sugar bags for Sweeter Sugar Inc.have an average weight of 16 ounces and a standard deviation of 0.3 ounces.The weights of the sugar packages are normally distributed.What is the probability that 9 randomly selected packages will have a weight in excess of 16.025 ounces?

Accepted Answer

A)  .5987
B)  .0062
C)  .4013
D)  .9938E) A) and C)
F) All of the above

Question 2

If we have a sample size of 100 and the estimate of the population proportion is .10,what is the mean of the sampling distribution of the sample proportion?

Accepted Answer

A)  0.0009
B)  0.10
C)  0.03
D)  0.90
E)  0.09F) A) and D)
G) B) and D)

Question 3

Whenever the population has a normal distribution,the sampling distribution of  Xˉ\bar { X }Xˉ 
Is normal or near normal distribution:

Accepted Answer

A)  For only large sample sizes.
B)  For only small sample sizes.
C)  For any sample size.
D)  For only samples of size 30 or more. E) None of the above
F) A) and B)

Question 4

Suppose that 60 percent of the voters in a particular region support a candidate.Find the probability that a sample of 1,000 voters would yield a sample proportion in favor of the candidate within 4 percentage points of the actual proportion.

Accepted Answer

A)  .0155
B)  .9952
C)  .9484
D)  .9902E) None of the above
F) A) and D)

Question 5

In a manufacturing process,a machine produces bolts that have an average length of 3 inches with a variance of .03.If we randomly select three bolts from this process,What is the probability the mean length of the bolt is at least 3.16 inches?

Accepted Answer

A)  97.72%
B)  5.48%
C)  94.52%
D)  44.52%
E)  2.28%F) A) and D)
G) B) and D)

Question 6

Consider two population distributions labeled A and B.Distribution A is highly skewed and nonnormal,while distribution B is slightly skewed and near normal.In order for the sampling distributions of A and B to achieve the same degree of normality:

Accepted Answer

A)  Population A will require a larger sample size.
B)  Population B will require a larger sample size.
C)  Populations A and B will require the same sample size.
D)  None of these.E) A) and B)
F) All of the above

Question 7

If a population distribution is known to be normal,then it follows that:

Accepted Answer

A)  The sample mean must equal the population mean.
B)  The sample mean must equal the population mean for large samples.
C)  The sample standard deviation must equal the population standard deviation.
D)  All of these.
E)  None of thesE.F) A) and E)
G) B) and C)

Question 8

In the upcoming governor's election,the most recent poll,based on 900 respondents,predicts that the incumbent will be reelected with 55 percent of the votes.What is  σXˉ\sigma _ { \bar { X } }σXˉ​ 
?

Accepted Answer

A)  .00825
B)  .0166
C)  .0247
D)  .0003 E) B) and D)
F) B) and C)

Question 9

The ______________ of a sample statistic is the probability distribution of the population of all possible values of the sample statistic.

Accepted Answer

A)  Sample mean
B)  Sampling distribution
C)  Probability
D)  ObservationsE) A) and C)
F) C) and D)

Question 10

A random sample of size 36 is taken from a population with mean 50 and standard deviation 5.Find   49 ) ">P(Xˉ>49) \mathrm { P } ( \bar { X } > 49 ) P(Xˉ>49)

Accepted Answer

A)  .8331
B)  .1151
C)  .8849
D)  .1389 E) C) and D)
F) None of the above

Question 11

If the sampled population is exactly normally distributed,then the sampling distribution of $\bar { X }$ 
is also expected to be normal,regardless of the sample size.

Accepted Answer

A) True 
 B)False

Question 12

If the sample size n is infinitely large,then s2 is an unbiased estimator of σ2.

Accepted Answer

A) True 
 B)False

Question 13

In random sampling without replacement,each element in the sample will be different.

Accepted Answer

A) True 
 B)False

Question 14

The reason sample variance has a divisor of n - 1 rather than n is that it makes the variance an unbiased estimate of the population variance.

Accepted Answer

A) True 
 B)False

Question 15

It has been reported that the average time to download the home page from a government website was 0.9 seconds.Suppose that the download times were normally distributed with a standard deviation of 0.3 seconds.If random samples of 23 download times are selected,describe the shape of the sampling distribution and how it was determined.

Accepted Answer

A)  Normal;size of sample meets the Central Limit Theorem requirement.
B)  Normal;the original population is normal.
C)  Skewed;the original population is not a normal distribution.
D)  Cannot be determined with the information that is given.E) C) and D)
F) None of the above

Question 16

A manufacturing company measures the weight of boxes before shipping them to the customers.If the box weights have a population mean and standard deviation of 90 lbs.and 24 lbs.respectively,then based on a sample size of 36 boxes,what is the probability that the average weight of the boxes will be less than 84 lbs.?

Accepted Answer

A)  16.87%
B)  93.32%
C)  43.32%
D)  6.68%
E)  84.13%F) C) and D)
G) None of the above

Question 17

If we have a sample size of 100 and the estimate of the population proportion is .10,what is the standard deviation of the sampling distribution of the sample proportion?

Accepted Answer

A)  .0009
B)  .03
C)  3
D)  .01
E)  .10F) A) and B)
G) A) and C)

Question 18

Find  P(395.4<Xˉ<404.6) \mathrm { P } ( 395.4 < \bar { X } < 404.6 ) P(395.4<Xˉ<404.6)  
If the population mean = 400,?x = 20,and n = 100.

Accepted Answer

A)  .9786
B)  .9999
C)  .0214
D)  .9893 E) B) and C)
F) None of the above

Question 19

There is no easy way to calculate an unbiased point estimate of σ.

Accepted Answer

A) True 
 B)False

Question 20

If p = .9 and n = 40,then we can conclude that the sampling distribution of $\hat { p }$ 
is approximately a normal distribution.

Accepted Answer

A) True 
 B)False

Exam 7: Sampling and Sampling Distributions

If the sample size n is infinitely large,then s² is an unbiased estimator of σ².

Correct Answer
verified

In the upcoming governor's election,the most recent poll,based on 900 respondents,predicts that the incumbent will be reelected with 55 percent of the votes.What is $\sigma _ { \bar { X } }$ ?

Correct Answer
verified

Correct Answer
verified

Find $\mathrm { P } ( 395.4 < \bar { X } < 404.6 )$ If the population mean = 400,?_x = 20,and n = 100.

Correct Answer
verified

A random sample of size 36 is taken from a population with mean 50 and standard deviation 5.Find $\mathrm { P } ( \bar { X } > 49 )$

Correct Answer
verified

If we have a sample size of 100 and the estimate of the population proportion is .10,what is the standard deviation of the sampling distribution of the sample proportion?

Correct Answer
verified

The reason sample variance has a divisor of n - 1 rather than n is that it makes the variance an unbiased estimate of the population variance.

Correct Answer
verified

If the sampled population is exactly normally distributed,then the sampling distribution of $\bar { X }$ is also expected to be normal,regardless of the sample size.

Correct Answer
verified

If we have a sample size of 100 and the estimate of the population proportion is .10,what is the mean of the sampling distribution of the sample proportion?

Correct Answer
verified

There is no easy way to calculate an unbiased point estimate of σ.

Correct Answer
verified

Suppose that 60 percent of the voters in a particular region support a candidate.Find the probability that a sample of 1,000 voters would yield a sample proportion in favor of the candidate within 4 percentage points of the actual proportion.

Correct Answer
verified

The ______________ of a sample statistic is the probability distribution of the population of all possible values of the sample statistic.

Correct Answer
verified

If a population distribution is known to be normal,then it follows that:

Correct Answer
verified

In random sampling without replacement,each element in the sample will be different.

Correct Answer
verified

Packages of sugar bags for Sweeter Sugar Inc.have an average weight of 16 ounces and a standard deviation of 0.3 ounces.The weights of the sugar packages are normally distributed.What is the probability that 9 randomly selected packages will have a weight in excess of 16.025 ounces?

Correct Answer
verified

In a manufacturing process,a machine produces bolts that have an average length of 3 inches with a variance of .03.If we randomly select three bolts from this process,What is the probability the mean length of the bolt is at least 3.16 inches?

Correct Answer
verified

Correct Answer
verified

Whenever the population has a normal distribution,the sampling distribution of $\bar { X }$ Is normal or near normal distribution:

Correct Answer
verified

Consider two population distributions labeled A and B.Distribution A is highly skewed and nonnormal,while distribution B is slightly skewed and near normal.In order for the sampling distributions of A and B to achieve the same degree of normality:

Correct Answer
verified

If p = .9 and n = 40,then we can conclude that the sampling distribution of $\hat { p }$ is approximately a normal distribution.

Correct Answer
verified

Exam 7: Sampling and Sampling Distributions

If the sample size n is infinitely large,then s2 is an unbiased estimator of σ2.

Correct AnswerverifiedShow Answer

In the upcoming governor's election,the most recent poll,based on 900 respondents,predicts that the incumbent will be reelected with 55 percent of the votes.What is σXˉ\sigma _ { \bar { X } }σXˉ​ ?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Find P(395.4<Xˉ<404.6) \mathrm { P } ( 395.4 < \bar { X } < 404.6 ) P(395.4<Xˉ<404.6) If the population mean = 400,?x = 20,and n = 100.

Correct AnswerverifiedShow Answer

A random sample of size 36 is taken from a population with mean 50 and standard deviation 5.Find P(Xˉ>49) \mathrm { P } ( \bar { X } > 49 ) P(Xˉ>49)

Correct AnswerverifiedShow Answer

If we have a sample size of 100 and the estimate of the population proportion is .10,what is the standard deviation of the sampling distribution of the sample proportion?

Correct AnswerverifiedShow Answer

The reason sample variance has a divisor of n - 1 rather than n is that it makes the variance an unbiased estimate of the population variance.

Correct AnswerverifiedShow Answer

If the sampled population is exactly normally distributed,then the sampling distribution of Xˉ\bar { X }Xˉ is also expected to be normal,regardless of the sample size.

Correct AnswerverifiedShow Answer

If we have a sample size of 100 and the estimate of the population proportion is .10,what is the mean of the sampling distribution of the sample proportion?

Correct AnswerverifiedShow Answer

There is no easy way to calculate an unbiased point estimate of σ.

Correct AnswerverifiedShow Answer

Suppose that 60 percent of the voters in a particular region support a candidate.Find the probability that a sample of 1,000 voters would yield a sample proportion in favor of the candidate within 4 percentage points of the actual proportion.

Correct AnswerverifiedShow Answer

The ______________ of a sample statistic is the probability distribution of the population of all possible values of the sample statistic.

Correct AnswerverifiedShow Answer

If a population distribution is known to be normal,then it follows that:

Correct AnswerverifiedShow Answer

In random sampling without replacement,each element in the sample will be different.

Correct AnswerverifiedShow Answer

Packages of sugar bags for Sweeter Sugar Inc.have an average weight of 16 ounces and a standard deviation of 0.3 ounces.The weights of the sugar packages are normally distributed.What is the probability that 9 randomly selected packages will have a weight in excess of 16.025 ounces?

Correct AnswerverifiedShow Answer

In a manufacturing process,a machine produces bolts that have an average length of 3 inches with a variance of .03.If we randomly select three bolts from this process,What is the probability the mean length of the bolt is at least 3.16 inches?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Whenever the population has a normal distribution,the sampling distribution of Xˉ\bar { X }Xˉ Is normal or near normal distribution:

Correct AnswerverifiedShow Answer

Consider two population distributions labeled A and B.Distribution A is highly skewed and nonnormal,while distribution B is slightly skewed and near normal.In order for the sampling distributions of A and B to achieve the same degree of normality:

Correct AnswerverifiedShow Answer

If p = .9 and n = 40,then we can conclude that the sampling distribution of p^\hat { p }p^​ is approximately a normal distribution.

Correct AnswerverifiedShow Answer

If the sample size n is infinitely large,then s² is an unbiased estimator of σ².

Correct Answer
verified

In the upcoming governor's election,the most recent poll,based on 900 respondents,predicts that the incumbent will be reelected with 55 percent of the votes.What is $\sigma _ { \bar { X } }$ ?

Correct Answer
verified

Correct Answer
verified

Find $\mathrm { P } ( 395.4 < \bar { X } < 404.6 )$ If the population mean = 400,?_x = 20,and n = 100.

Correct Answer
verified

A random sample of size 36 is taken from a population with mean 50 and standard deviation 5.Find $\mathrm { P } ( \bar { X } > 49 )$

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

If the sampled population is exactly normally distributed,then the sampling distribution of $\bar { X }$ is also expected to be normal,regardless of the sample size.

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Whenever the population has a normal distribution,the sampling distribution of $\bar { X }$ Is normal or near normal distribution:

Correct Answer
verified

Correct Answer
verified

If p = .9 and n = 40,then we can conclude that the sampling distribution of $\hat { p }$ is approximately a normal distribution.

Correct Answer
verified