Question 1

The sampling error is the

Accepted Answer

A)  same as the standard error of the mean. 
B)  difference between the value of the sample mean and the value of the population mean. 
C)  error caused by selecting a bad sample. 
D)  standard deviation multiplied by the sample size.

Question 2

Which of the following statements about cluster sampling is false?​

Accepted Answer

A)  ​All elements within the randomly selected clusters form the sample 
B)  ​It generally requires a smaller total sample size than simple random sampling 
C)  ​Ideally, each cluster is a representative small-scale version of the entire population 
D)  ​It provides the best results when the elements within the clusters are not alike

Question 3

The desired situation is when the sampled population is _____ the targeted population.

Accepted Answer

A)  identical to 
B)  larger than 
C)  smaller than 
D)  more varied than

Question 4

There are 7 children in a family.The number of children defines a population.The number of simple random samples of size 2 (without replacement) which are possible equals

Accepted Answer

A)  14. 
B)  21. 
C)  5. 
D)  42.

Question 5

A finite population correction factor is needed in computing the standard deviation of the sampling distribution of sample means

Accepted Answer

A)  whenever the population is infinite. 
B)  whenever the sample size is more than 5% of the population size. 
C)  whenever the sample size is less than 5% of the population size. 
D)  irrespective of the size of the sample.

Question 6

Cluster sampling is

Accepted Answer

A)  a nonprobability sampling method. 
B)  the same as convenience sampling. 
C)  a probability sampling method. 
D)  a systematic sampling method.

Question 7

In computing the standard error of the mean, the finite population correction factor is used when

Accepted Answer

A)  N/n > 0.05. 
B)  N/n  0.05. 
C)  n/N > 0.05. 
D)  n/N  30.

Question 8

The expected value of equals the mean of the population from which the sample is drawn​

Accepted Answer

A)  ​only if the sample size is 30 or greater. 
B)  ​only if the sample size is 50 or greater. 
C)  ​only if the sample size is 100 or greater. 
D)  ​for any sample size.

Question 9

A random sample of 144 bottles of cologne showed an average content of 4 ounces.It is known that the standard deviation of the contents (i.e., of the population) is 0.3 ounces.The standard error of the mean equals

Accepted Answer

A)  0.3333. 
B)  0.15. 
C)  0.025. 
D)  4.000.

Question 10

When the population has a normal distribution, the sampling distribution of  is normally distributed for any sample

Accepted Answer

A)  size. 
B)  size of 30 or more. 
C)  size of 50 or more. 
D)  from a finite population.

Question 11

As the sample size increases, the

Accepted Answer

A)  standard deviation of the population decreases. 
B)  population mean increases. 
C)  standard error of the mean decreases. 
D)  standard error of the mean increases.

Question 12

A population has a mean of 60 and a standard deviation of 18.A sample of 81 observations will be taken.The probability that the sample mean will be larger than 64 is

Accepted Answer

A)  0.5228. 
B)  0.9772. 
C)  0.4772. 
D)  0.0228.

Question 13

Random samples of size 64 are taken from an infinite population whose mean and standard deviation are 24 and 6.4, respectively.The distribution of the population is unknown.The mean and the standard error of the mean are

Accepted Answer

A)  64 and 6.4. 
B)  64 and 0.8. 
C)  24 and 6.4. 
D)  24 and 0.8.

Question 14

In a local university, 70% of the students live in the dormitories.A random sample of 75 students is selected for a particular study.The probability that the sample proportion (the proportion living in the dormitories) is between 0.69 and 0.72 is

Accepted Answer

A)  0.7778. 
B)  0.2222. 
C)  0.2347. 
D)  0.7653.

Question 15

A population consists of 500 elements.We want to draw a simple random sample of 50 elements from this population.On the first selection, the probability of an element being selected is

Accepted Answer

A)  0.100. 
B)  0.010. 
C)  0.001. 
D)  0.002.

Question 16

As a rule of thumb, the sampling distribution of the sample proportions can be approximated by a normal probability distribution whenever

Accepted Answer

A)  np ≥5, n ≥30. 
B)  np ≥5 and n(1-p) ≥5. 
C)  n  30 and (1 - p) = 0.5. 
D)  none of these alternatives is correct.

Question 17

A sample of 66 observations will be taken from an infinite population.The population proportion equals 0.12.The probability that the sample proportion will be less than 0.1969 is

Accepted Answer

A)  0.0955. 
B)  0.9045. 
C)  0.0273. 
D)  0.9727.

Question 18

Which of the following is NOT an example of nonsampling error?

Accepted Answer

A)  Coverage error 
B)  Measurement error 
C)  Interviewer error 
D)  Statistical error

Question 19

A sample of 400 observations will be taken from an infinite population.The population proportion equals 0.8.The probability that the sample proportion will be greater than 0.75 is

Accepted Answer

A)  0.8764. 
B)  0.1236. 
C)  0.9938. 
D)  0.0062.

Question 20

A population of size 1,000 has a proportion of 0.5.Therefore, the proportion and the standard deviation of the sample proportion for samples of size 100 are

Accepted Answer

A)  500 and 0.047. 
B)  500 and 0.050. 
C)  0.5 and 0.047. 
D)  0.5 and 0.050.

Exam 7: Sampling and Sampling Distributions