The correct answer is B. Stratified sampling is used since the field is divided into subplots and a random sample is taken from each subplot.
Explanation:
Sampling refers to the process followed by researchers to select a group of individuals from a larger group; considering in most studies it is not possible to analyze all the population. In the case of stratified sampling, this involves dividing the general population into smaller groups, which are known as strata; after this, the researcher selects a specific number of individuals from each strata. This method guarantees the sample is selected randomly, and therefore the study is not biased. Stratified sampling was the method used in the example described because, in this, the general population (46-acre field) was divided into subplots that represent the strata. Also, after this, the researcher selected one random sample.
The answer would be that Mario finished his homework at 3:55
"The intersection (∩) of a pair of sets (G and H) is a third set (I) composed by the elements that belong, at the same time, to both given sets."
According to this definition:
Given the sets:
G = {3, 7, 8, 9}
H = {2, 5, 7, 8}
The Intersection is:
G ∩ H = I = {7, 8}
:-)
