Question 1

The possible presence of hidden periodicities is a danger of _______ sampling.

Accepted Answer

A)  stratified 
B)  cluster 
C)  simple random 
D)  systematic

Question 2

The variance of the sampling distribution can be equal to the variance of the population.

Accepted Answer

A) True 
 B)False

Question 3

A random sample of size 36 is selected from a population of size 101 whose standard deviation is 5 . The standard error of the mean is _______.

Accepted Answer

The answer of A random sample of size 36 is...

Question 4

The mean number of errors in a random sample of 100 accounts to be audited is used to estimate the mean of the population of accounts having a standard deviation of $\sigma=4$. What is the probability that the error will be less than 0.8
-using the central limit theorem?

Accepted Answer

The answer of The mean number of errors in a...

Question 5

If we want to change a standard error from 12 to 4 by changing the sample size, we need to multiply the original sample size by

Accepted Answer

A)  3 . 
B)  9 . 
C)  $\frac{1}{3}$. 
D)  $\frac{1}{9}$.

Question 6

It is impossible to apply the central limit theorem if the population does not follow a normal distribution.

Accepted Answer

A) True 
 B)False

Question 7

An investor considers investing in the stocks of the following companies: IBM, Honeywell, Mobil, Eastman Kodak, and Homestake Mining.
-In how many ways can the investor select two stocks to buy?

Accepted Answer

The answer of An investor considers investing in the stocks...

Question 8

A simple random sample from a finite population is a sample which is chosen in such a way that each possible sample has the same probability of being selected.

Accepted Answer

A) True 
 B)False

Question 9

Sampling with replacement from a finite population is, in effect, sampling from an infinite population.

Accepted Answer

A) True 
 B)False

Question 10

An important goal of _______ sampling is that there is less variability within the resulting subgroups than in the entire population.

Accepted Answer

A)  stratified 
B)  cluster 
C)  quota 
D)  systematic

Question 11

Random samples of size 2 are selected from the finite population which consists of the numbers 4, 7, 10, 13, 16, and 19.
-List the 15 possible random samples of size 2 that can be selected from the finite population, and calculate their means.

Accepted Answer

The answer of Random samples of size 2 are selected...

Question 12

The central limit theorem applies in situations when $n$ constitutes a large proportion of the population.

Accepted Answer

A) True 
 B)False

Question 13

A stratified sample is taken from a population of size $N=2000$ which consists of two strata of $N_{1}=800$, $N_{2}=1200, n_{1}=20, n_{2}=40, \sigma_{1}=3, \sigma_{2}=5$. Then the method of allocation is

Accepted Answer

A)  proportional. 
B)  optimum. 
C)  neither proportional nor optimum. 
D)  both proportional and optimum.

Question 14

The mean of a random sample of size 49 is used to estimate the mean of a very large population, consisting of the lifetimes of certain stereo components which have a standard deviation of $\sigma=35$ hours. What is the probability that our estimate will be in error by
-less than 8 hours?

Accepted Answer

The answer of The mean of a random sample of...

Question 15

In order for $\sigma_{\bar{\chi}}^{\bar{x}}$ to be as low as possible in stratified sampling, it is preferable that each of the strata have as little homogeneity as possible.

Accepted Answer

A) True 
 B)False

Question 16

A sampling distribution of the mean is always a probability distribution whose values are sample means.

Accepted Answer

A) True 
 B)False

Question 17

A stratified sample of size $n=300$ is to be taken from a population of size $N=30,000$ which consists of four strata for which $N_{1}=10,000, N_{2}=5,000, N_{3}=8,000, N_{4}=7,000, \sigma_{1}=15, \sigma_{2}=25, \sigma_{3}=20$ and $\sigma_{4}=30$. How large a sample must be taken from each stratum if the allocation is to be
-optimum?

Accepted Answer

The answer of A stratified sample of size $n=300$ is...

Question 18

Suppose that in a group of six athletes there are three jockeys whose heights are 60,65 , and 55 inches, and three basketball players whose heights are 80,75 , and 85 inches.
-Suppose that the six athletes are divided into clusters according to their sports, each cluster is assigned a probability of $\frac{1}{2}$, and a random sample of size 2 is taken from one of the randomly chosen clusters. List all possible samples, calculate their means, and calculate $\sigma_{\bar{x}}$.

Accepted Answer

The answer of Suppose that in a group of six...

Question 19

Using the population of the numbers $10,38,25,18,42,15$, construct the sampling distribution of the median for random samples of size $n=3$ drawn without replacement from the given population.

Accepted Answer

The answer of Using the population of the numbers $10,38,25,18,42,15$,...

Question 20

Suppose that in a group of six athletes there are three jockeys whose heights are 60,65 , and 55 inches, and three basketball players whose heights are 80,75 , and 85 inches.
-List all possible random samples of size 2 which may be taken from this population. Calculate the means of these samples, and calculate $\sigma_{\bar{x}}$.

Accepted Answer

The answer of Suppose that in a group of six...

Exam 10: Sampling and Sampling Distributions

The possible presence of hidden periodicities is a danger of _______ sampling.

The variance of the sampling distribution can be equal to the variance of the population.

A random sample of size 36 is selected from a population of size 101 whose standard deviation is 5 . The standard error of the mean is _______.

The mean number of errors in a random sample of 100 accounts to be audited is used to estimate the mean of the population of accounts having a standard deviation of $\sigma=4$ . What is the probability that the error will be less than 0.8 -using the central limit theorem?

If we want to change a standard error from 12 to 4 by changing the sample size, we need to multiply the original sample size by

It is impossible to apply the central limit theorem if the population does not follow a normal distribution.

An investor considers investing in the stocks of the following companies: IBM, Honeywell, Mobil, Eastman Kodak, and Homestake Mining. -In how many ways can the investor select two stocks to buy?

A simple random sample from a finite population is a sample which is chosen in such a way that each possible sample has the same probability of being selected.

Sampling with replacement from a finite population is, in effect, sampling from an infinite population.

An important goal of _______ sampling is that there is less variability within the resulting subgroups than in the entire population.

Random samples of size 2 are selected from the finite population which consists of the numbers 4, 7, 10, 13, 16, and 19. -List the 15 possible random samples of size 2 that can be selected from the finite population, and calculate their means.

The central limit theorem applies in situations when $n$ constitutes a large proportion of the population.

A stratified sample is taken from a population of size $N=2000$ which consists of two strata of $N_{1}=800$ , $N_{2}=1200, n_{1}=20, n_{2}=40, \sigma_{1}=3, \sigma_{2}=5$ . Then the method of allocation is

The mean of a random sample of size 49 is used to estimate the mean of a very large population, consisting of the lifetimes of certain stereo components which have a standard deviation of $\sigma=35$ hours. What is the probability that our estimate will be in error by -less than 8 hours?

In order for $\sigma_{\bar{\chi}}^{\bar{x}}$ to be as low as possible in stratified sampling, it is preferable that each of the strata have as little homogeneity as possible.

A sampling distribution of the mean is always a probability distribution whose values are sample means.

Using the population of the numbers $10,38,25,18,42,15$ , construct the sampling distribution of the median for random samples of size $n=3$ drawn without replacement from the given population.

Exam 10: Sampling and Sampling Distributions

The possible presence of hidden periodicities is a danger of _______ sampling.

The variance of the sampling distribution can be equal to the variance of the population.

A random sample of size 36 is selected from a population of size 101 whose standard deviation is 5 . The standard error of the mean is _______.

The mean number of errors in a random sample of 100 accounts to be audited is used to estimate the mean of the population of accounts having a standard deviation of σ=4\sigma=4σ=4 . What is the probability that the error will be less than 0.8 -using the central limit theorem?

If we want to change a standard error from 12 to 4 by changing the sample size, we need to multiply the original sample size by

It is impossible to apply the central limit theorem if the population does not follow a normal distribution.

An investor considers investing in the stocks of the following companies: IBM, Honeywell, Mobil, Eastman Kodak, and Homestake Mining. -In how many ways can the investor select two stocks to buy?

A simple random sample from a finite population is a sample which is chosen in such a way that each possible sample has the same probability of being selected.

Sampling with replacement from a finite population is, in effect, sampling from an infinite population.

An important goal of _______ sampling is that there is less variability within the resulting subgroups than in the entire population.

Random samples of size 2 are selected from the finite population which consists of the numbers 4, 7, 10, 13, 16, and 19. -List the 15 possible random samples of size 2 that can be selected from the finite population, and calculate their means.

The central limit theorem applies in situations when nnn constitutes a large proportion of the population.

The mean of a random sample of size 49 is used to estimate the mean of a very large population, consisting of the lifetimes of certain stereo components which have a standard deviation of σ=35\sigma=35σ=35 hours. What is the probability that our estimate will be in error by -less than 8 hours?

In order for σχˉxˉ\sigma_{\bar{\chi}}^{\bar{x}}σχˉ​xˉ​ to be as low as possible in stratified sampling, it is preferable that each of the strata have as little homogeneity as possible.

A sampling distribution of the mean is always a probability distribution whose values are sample means.

Using the population of the numbers 10,38,25,18,42,1510,38,25,18,42,1510,38,25,18,42,15 , construct the sampling distribution of the median for random samples of size n=3n=3n=3 drawn without replacement from the given population.

The mean number of errors in a random sample of 100 accounts to be audited is used to estimate the mean of the population of accounts having a standard deviation of $\sigma=4$ . What is the probability that the error will be less than 0.8 -using the central limit theorem?

The central limit theorem applies in situations when $n$ constitutes a large proportion of the population.

The mean of a random sample of size 49 is used to estimate the mean of a very large population, consisting of the lifetimes of certain stereo components which have a standard deviation of $\sigma=35$ hours. What is the probability that our estimate will be in error by -less than 8 hours?

In order for $\sigma_{\bar{\chi}}^{\bar{x}}$ to be as low as possible in stratified sampling, it is preferable that each of the strata have as little homogeneity as possible.

Using the population of the numbers $10,38,25,18,42,15$ , construct the sampling distribution of the median for random samples of size $n=3$ drawn without replacement from the given population.