The question is incomplete. Here is the complete question.
For each situation identify which sampling method should be used. (simple random, stratified, cluster or systematic sample)
(a) A farmer has 44 plots of land for growing corn. He is concerned that the variation in yield between plots will vary but not within plots.
(b) Out of the 18 sections of Calculus, the chair of the math department randomly selected 4 sections. He then gives students in two of the four sections a paper exam, while the other two sections receive an online exam. Scores were then compared.
(c) A class of 250 students is numbered form 1 to 250 and a table of random digits is used to choose 55 students from the class. What type of sampling is used to select the group of students?
(d) In a factory producing television sets, every 100th set produced is inspected.
Answer and Step-by-step explanation:
Situation in (a) is called Cluster, where researchers divide the population into multiple groups. They analyze a sample of multiple sample parameters. The method is used when the groups that are internally different but are very similar form a population.
Situation in (b) is the method called Stratified, in which, a researcher finds difficult to analyse an entire population. So he/she divides this population into homogenous groups called strata (or stratum for plural) Fform each subgroup a random sample is selected.
Situation in (c) is the Sample Random: every item in the entire population has the same chance of being selected to create a sample.
Situation in (d) is the Systematic Sample, in which the sample is selected according to a starting position with a fixed periodic interval, as described in the situation.