Question

news cameras take an overhead picture of a part of a crowd at an outdoor event. journalists then count the number of people in the picture and use the sample to estimate the total number of people in the crowd. this process is an example of
random sampling.
stratified sampling.
systematic random sampling.
cluster sampling.

Explanation:

To determine the sampling method, we analyze each option:

• Random sampling: Involves selecting individuals randomly from the entire population. Here, the sample is a part of the crowd (a cluster) rather than random individuals.
• Stratified sampling: Divides the population into strata (groups) and samples from each. The crowd isn't divided into strata here.
• Systematic random sampling: Selects every k-th individual. This isn't the case here.
• Cluster sampling: Divides the population into clusters (groups), and a whole cluster is sampled. The overhead picture of a part of the crowd is a cluster (a group of people in that area), and this cluster is used to estimate the total. So this matches cluster sampling.

Answer:

D. cluster sampling