Final answer:
The statistical study in question, where the pizza parlor owner calls every fifth person who ordered pizza to rate it, is best classified as a survey. This type of study is used to gather feedback or opinions from a sample of the population to represent the whole.
Step-by-step explanation:
The question posed relates to the categorization of a particular method of collecting statistical data in which the owner of a pizza parlor calls every fifth person who ordered pizza to rate the pizza. When considering the options provided, the scenario described does not fit the definition of an experiment because it lacks any manipulation of variables. This situation is not a census because it does not attempt to include every individual in the population. Neither can it be classified as an observational study because the data collection involves actively reaching out to participants for specific responses rather than passively observing and recording behaviors or outcomes.
Therefore, the correct option for the type of statistical study being conducted is a survey. Surveys are a method of research in which a subset of the population is questioned to represent the entire population's opinions or behaviors. Surveys are used in various fields, including marketing, to gather customer feedback, preferences, and satisfaction levels. In this case, the pizza parlor owner is surveying to assess customer satisfaction with their pizza. Surveys often include incentives for completion and can target specific demographic groups or the general population depending on the research objective.