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:

Random sampling involves selecting a subset of individuals from a population where each individual has an equal chance of being chosen. In this case, an overhead picture of a part of the crowd is taken without any specific stratification, systematic pattern, or clustering - just a random part of the crowd is used as a sample to estimate the total number. Stratified sampling divides the population into subgroups (strata) and samples from each stratum. Systematic random sampling selects elements at regular intervals. Cluster sampling divides the population into clusters and samples entire clusters. Since none of these more complex sampling methods are described, it's random sampling.

Answer:

random sampling.