Final answer:
Percentages can be calculated in an aggregate observation session, which is a statistical method that compiles data from various sources to provide a comprehensive view. The term 'aggregate' refers to the whole formed by combining several elements.
Step-by-step explanation:
Percentage can be calculated for different types of observation sessions. When looking at the provided options, percentages can apply to any observational or experimental scenario where frequency, amount, proportion, or comparisons are pertinent. In statistics, a percentage is a quantitative expression that represents a fraction of 100. Thus, it is conceivable to calculate a percentage in an aggregate observation session where collective data from various observations or experiments are compiled for analysis.
The term aggregate refers to the whole formed by combining several elements. In statistics, aggregating data means compiling data from several different sources or over a period to provide a summary or comprehensive view.