Please see the attached file.

Question 1 Multiple Choice
All of the following are reasons to sample except for:
Reduce sampling error
The research process is sometimes destructive.
Save time
For given resources, broaden the scope of the study.

Answer: Reduce sampling error

Question 2 Multiple Choice
Sampling in which every unit of the population has the same probability of being selected into the sample is sometimes referred to as:
representative sampling
fair sampling
random sampling
nonrandom sampling

Answer: random sampling

Question 3 Multiple Choice
The most elementary random sampling technique is:
simple random sampling
stratified random sampling
systematic random sampling
area random sampling

Answer: simple random sampling

Question 4 Multiple Choice
In which of the following sampling techniques does the researcher number every item of the population before taking the sample?
systematic sampling
quota sampling
cluster sampling
simple random sampling

Answer: systematic sampling

Question 5 Multiple Choice
The main reason for using stratified random sampling is to:
reduce costs
make certain that every kth item is selected
reduce sampling error
reduce non sampling error

Answer: reduce costs

Question 6 Multiple Choice
Fifty percent of a population possesses attribute X, thirty percent possesses attribute Y, and twenty percent possesses attribute Z. A researcher decides to include some people with attribute X, some with attribute Y, and some with attribute Z in her sample. Her sample consists of 80 people with attribute X, 70 people with attribute Y, and 50 people with attribute Z. The researcher has most likely done what type of sampling?
systematic sampling
simple random sampling
proportionate stratified sampling
disproportionate stratified sampling

Answer: disproportionate stratified sampling

X= 80 40% 50%
Y= 70 35% 30%
Z= 50 25% 20%
200
Therefore, disproportionate stratified sampling

Question 7 Multiple Choice
Another name for cluster sampling is:
stratified sampling
quota sampling
snowball sampling
area sampling

Answer: area sampling

Question 8 Multiple Choice
Test markets are probably closest to which type of sampling?
cluster sampling
quota sampling
stratified sampling
snowball sampling

Answer: quota sampling

Quota sampling is a method of sampling widely used in opinion polling and market research.

Question 9 Multiple Choice
In using judgment sampling, the researcher attempts to sample elements from the population by using her judgment. However, the researcher tends to make errors of judgment in one direction. These systematic errors are called:
consistencies
directional errors
biases
tendencies

Answer: biases

Question 10 Multiple Choice
Which of the following sampling techniques is based on referral?
stratified
quota
area
snowball

Answer: snowball

Question 11 Multiple Choice
The central limit theorem states that which of the following is true:

Answer:

Question 12 Multiple Choice
The central limit theorem states that for a given large sample size, if the shape of the population is unknown, the distribution of sample means is:
unknown
normal
platykurtic
skewed

Answer: normal

Question 13 Multiple Choice
Suppose a population has a mean of 75 and a standard deviation of 14. If a researcher randomly samples 35 values from this population, the probability that >=72 is

0.102
0.5832
0.398
0.898

Answer: 0.898

Mean=M = 75
Standard deviation =s= 14
sample size=n= 35
sx=standard error of mean=s/square root of n= 2.3664 = ( 14 /square root of 35)
xbar= 72
z=(xbar-M )/sx= -1.2677 =(72-75)/2.3664
Cumulative Probability corresponding to z= -1.2677 is= 0.1025
Or Probability corresponding to xbar< 72.00 is Prob(Z)= 0.1025
Therefore probability corresponding to xbar> 72.00 is 1-Prob(Z)= 0.8975 =1-0.1025

Question 14 Multiple Choice
Suppose a population has a mean of 84 and a standard deviation of 18. If a researcher randomly samples 37 values from this population, the probability that 80 <= <=89

0.866
0.043
0.1331
0.3669

Answer: 0.866

Mean=M = 84
Standard deviation =s= 18
sample size=n= 37
sx=standard error of mean=s/square root of n= 2.9592 = ( 18 /square root of 37)
x1 bar = 80
x2bar= 89
z1=(x1bar -M )/sx= -1.3517 =(80-84)/2.9592
z2=(x2bar-M )/sx= 1.6896 =(89-84)/2.9592

Cumulative Probability corresponding to z1= -1.3517 is= 0.0882 0r= 8.82%
Cumulative Probability corresponding to z2= 1.6896 is= 0.9544 0r= 95.44%

Therefore probability that the value of x will be between x1bar= 80 and x2 bar= 89
is = 86.62% =95.44%-8.82%

Question 15 Multiple Choice
Suppose a population has a mean of 152 and a standard deviation of 22. If a researcher is randomly taking samples of size 42 from the population, 63% of the sample means are greater than what value?
153.12
151.56
150.88
154.64

Answer: 153.12

Mean=M = 152.00
Standard deviation =s= 22.00
sample size=n= 42
sx=standard error of mean=s/square root of n= 3.3947 = ( 22 /square root of 42)
Z corresponding to 63% is 0.3319
z=(x-M )/s or x=M +z*s
or x=152+0.3319*3.3947= 153.13

Question 16 Multiple Choice
The Central Limit Theorem applies to sample proportions if sample size is large enough relative to the population proportion. How large of a sample size is needed?
n? p = .25
n? p> 5 and n? q> 5
n >= 30
n? p> 7 and n< 20

Answer: n >= 30

Question 17 Multiple Choice
Fifty-seven percent of the population has heard of brand x batteries. If 340 people are randomly selected from the population, what is the probability that the sample proportion who have heard of brand x batteries is greater than sixty percent?
0.1314
0.2755
0.3686
0.8686

Answer: 0.1314

p= 57.00%
q=1-p= 43.00%
n=sample size= 340
sp=standard error of proportion=square root of (pq/n)= 2.685% =square root of ( 57.% * 43.% / 340)
pbar= 60%
z=(pbar-M )/sp 1.1173 =(0.6-0.57)/0.02685
Cumulative Probability corresponding to z= 1.1173 is= 0.8681
Or Probability corresponding to pbar< 60% is Prob(Z)= 0.8681
Therefore probability corresponding to pbar> 60% is 1-Prob(Z)= 0.1319 =1-0.8681
0r= 13.19%

Question 18 Multiple Choice
Suppose that 78% of all prerecorded music shoppers are under age 30. If a random sample of 250 prerecorded music shoppers is randomly taken, what is the probability that the sample proportion that is under age 30 is more than 76%?
0.2764
0.7764
0.2236
0.8131

Answer: 0.7764

p= 78.00%
q=1-p= 22.00%
n=sample size= 250
sp=standard error of proportion=square root of (pq/n)= 2.620% =square root of ( 78.% * 22.% / 250)
pbar= 76%
z=(pbar-M )/sp -0.7634 =(0.76-0.78)/0.0262
Cumulative Probability corresponding to z= -0.7634 is= 0.2226
Or Probability corresponding to pbar< 76% is Prob(Z)= 0.2226
Therefore probability corresponding to pbar> 76% is 1-Prob(Z)= 0.7774 =1-0.2226
0r= 77.74%

Question 19 Multiple Choice
Suppose that 42% of all consumers who purchase bottled water from a supermarket prefer brand x. If a random sample of 425 such consumers is taken, what is the probability that between 35% and 38% prefer brand x?
0.0457
0.1056
0.3944
0.9507

Answer: 0.0457

p= 42.00%
q=1-p= 58.00%
n=sample size= 425
sp=standard error of proportion=square root of (pq/n)= 2.394% =square root of ( 42.% * 58.% / 425)
p1bar= 38%
p2 bar = 35%
z1=(p1bar-M )/sp= -1.6708 =(0.38-0.42)/0.02394
z2=(p2bar-M )/sp= -2.924 =(0.35-0.42)/0.02394

Cumulative Probability corresponding to z1= -1.6708 is= 0.0474 0r= 4.74%
Cumulative Probability corresponding to z2= -2.924 is= 0.0017 0r= 0.17%

Therefore probability that the value of pbar will be between p1bar= 38% and p2 bar= 35%
is = 4.57% =4.74%-.17% or 0.0457

Question 20 Multiple Choice
Suppose .27 of all workers would switch jobs if they had an opportunity. If 292 workers are randomly selected, what is the probability that between 82 and 90 would switch jobs if they had an opportunity?
0.1628
0.2651
0.4279
0.5907

Answer: 0.2651

p= 27.00%
q=1-p= 73.00%
n=sample size= 292
sp=standard error of proportion=square root of (pq/n)= 2.598% =square root of ( 27.% * 73.% / 292)
p1bar= 30.82% =90/292
p2 bar = 28.08% =82/292
z1=(p1bar-M )/sp= 1.4704 =(0.3082-0.27)/0.02598
z2=(p2bar-M )/sp= 0.4157 =(0.2808-0.27)/0.02598

Cumulative Probability corresponding to z1= 1.4704 is= 0.9293 0r= 92.93%
Cumulative Probability corresponding to z2= 0.4157 is= 0.6612 0r= 66.12%

Therefore probability that the value of pbar will be between p1bar= 30.82% and p2 bar= 28.08%
is = 26.81% =92.93%-66.12% or 0.2681