Master the Art of Random Sampling: Comprehensive Examples and Expert Advice

Joanne needs to test boxes of pasta to see if they contain the correct amount of product. Each of the 500 boxes in a recent batch has a unique serial number from 1001 to 1500 stamped on it. She will pick a random sample of 50 boxes by generating a random integer between 1001 and 1011 to select the first box, and then selecting every tenth number in sequence. Her method is called
A) cluster sampling.
B) convenience sampling.
C) multistage sampling.
D) stratified sampling.
E) systematic sampling.

A service agency wishes to assess clients' views of quality service over the past year. Computer records identify 1000 clients over the past 12 months and a decision is made to select 100 clients to survey. The 100 clients to survey are identified through assigning 1-1000 to the clients and a software package was used to randomly select 100 of them. Sampling Techniques:
A. Simple Random Sampling
B. Systematic Random Sampling
C. Stratified Sampling
D. Cluster Sampling

Kidly answert both parts
A researcher is interested in evaluating the earnings of airport staff in the United States (US). Suppose the US has about 5,200 airports. A decision is made to classify all 5,200 airports as distinct groups, where the employees of each airport represent a group. You then perform simple random sampling technique to select 100 airports from your 5,200 groups. The earnings of the employees in those 100 airports will represent the primary data for your study.
a) Did you perfom stratified random sampling or cluster sampling? Explain.
b) What advantage might it have other simple random sampling?

Determine if the following situations use random or nonrandom sampling. Then, identify what type of random or nonrandom sampling technique is used.
1. Respondents are chosen from a list in the telephone directory.
2. There are 30 freshmen, 20 sophomores, 10 juniors, and 5 seniors enrolled in a certain course. Samples are to be taken from them according to the total number of students per year level.
3. Minority groups of senators are to be interviewed.
4. Every five files out of 500 files will be chosen.
5. Animals going astray are to be observed.
6. Two thousand respondents nationwide, from regions down to barangays, are selected for a national election survey.
7. Five hundred “likes” in Facebook are used as a basis for making a decision.
8. Selected respondents for a study are those with Acquired Immune Deficiency Syndrome (AIDS).
9. Ten names of students were picked out from a box containing 1,000 names written in rolled papers.
10. Selected vehicles are classified according to the last number of their plates as odd or even.

Regarding simple random sampling:
a. What is simple random sampling?
b. What is a simple random sample?
c. Identify two forms of simple random sampling and explain the difference between the two.

A worker wanted to estimate the average annual living expenses for the residents of New Zealand. He randomly selected one of the suburbs and then collected the data for the annual living expenses for all residents.
Which of the sampling plans: simple random sampling, stratified random sampling or cluster sampling did the researcher use?
What are the advantage(s) and disadvantage(s) of the sampling plan used?

Which statement below is incorrect?
Select one:
A. In a survey study, we can never completely eliminate the random error, but it is possible to completely eliminate the systematic error.
B. Compared to the simple random sampling, it is easier to manipulate data with the systematic random sampling.
C. PACF and ACF can never have the same value.
D. If a time series has an upward trend over time, it cannot be stationary.

Surveys that combine one or more of simple random sampling, systematic random sampling, cluster sampling, and stratified sampling employ what is called sampling.

Extending the Concepts and Skills
In sampling from a population, state which type of sampling design corresponds to each of the following experimentaldesigns:
a. Completely randomized design
b. Randomized block design

The students in an Introductory Statistics class are asked to complete a survey about study habits.
(a) does the study appear to use random sampling?
yes or no
(b) does the study appear to use random assignment?
yes or no

When the Bureau of Labor Statistics conducts a survey, it begins by partitioning the United States adult popula- tion into 2,007 groups called primary sampling units Assume that these primary sampling units all contain the same number of adults. If you randomly select one adult from each primary sampling unit, is the result a simple random sample? Why or why not?

You will be required to select two different sampling methods, each method you will choose a random sample of 20 sentences from throughout the book by following the method you selected and count how many words contained in each sentence that was selected per your (random) sampling method. Use two different sampling methods, chosen from simple random sampling, stratified sampling, cluster sampling, or systematic sampling.
1. Explain which of your two methods was easier to use and why.
2. Of the two methods, you did not use, explain which of them would have been the most difficult to use and why.
3. Do you think either of your methods produced biased results? Explain.