Question

In Exercises 9–20, identify which of these types of sampling is used: random, systematic, convenience, stratified, or cluster.

Cormorant Density Cormorant bird population densities were studied by using the “line transect method” with aircraft observers flying along the shoreline of Lake Huron and collecting sample data at intervals of every 20 km (based on data from Journal of Great Lakes Research).

Short answer

Systematic sampling

Step-by-step solution

Given information

The study requires an analysis of the population densities of Cormorant birds.

The sample data was collected by aircraft observers at every 20 km interval while flying along the shoreline of Lake Huron.

Identify the method of sampling

Data is collected at an interval of 20 km through aircraft observers while flying along Lake Huron’s shoreline.

Here, each observation is collected in a fixed interval, which is 20km.

As the data is collected randomly along a fixed interval, the sampling is said to be done in a systematic manner.

Thus, it is systematic sampling.