Identify each sampling method listed below as simple random sample, systematic,
ID: 3202521 • Letter: I
Question
Identify each sampling method listed below as simple random sample, systematic, convenience, stratified, or cluster. A math professor wants to estimate the number of words per sentence in Calculus by Stewart. She randomly selects 20 pages and counts the number of words per sentence in every sentence on those pages. In a Pew Research Center poll, 1007 adults were called after their telephone numbers were randomly generated by a computer, and 85% of the respondents were able to correctly identify what Twitter is. A reporter for the school newspaper wrote an article about student's opinions of the new Rec Center after interviewing students he found hanging out in the Rec Center. When collecting data from different sample locations in a lake, a researcher uses the "line transect method" by stretching a rope across the lake and collecting samples at every' interval of 5 meters. A researcher collects data on the approval rating of the president by first dividing the population of the country' into three groups: urban, suburban, and rural. Then the researcher takes a simple random sample from each group.Explanation / Answer
(a) simple random sampling:
in this sampling method each individual is chosen entirely by chance and each member of the population has an equal chance of being included in the sample.
(b) cluster sampling:
Cluster sampling is a sampling technique used when "natural" but relatively heterogeneous groupings are evident in a statistical population.
(c) convenience sampling:
A convenience sample is one of the main types of non-probability samplingmethods. A convenience sample is made up of people who are easy to reach.
(d) systematic sampling:
Systematic sampling is a type of probability sampling method in which samplemembers from a larger population are selected according to a random starting point and a fixed periodic interval. This interval, called the sampling interval, is calculated by dividing the population size by the desired sample size.
(e) stratified sampling:
With stratified sampling, the researcher divides the population into separate groups, called strata. Then, a probability sample (often a simple random sample ) is drawn from each group.