Final answer:
The correct phrase to complete the sentence is 'a. Relative occurrence; potential'. A percentage is used to express the relative occurrence of an event compared to the potential total opportunities for the event to occur.
Step-by-step explanation:
A percentage expresses the relative occurrence quantity of some event in terms of the number of times the event occurred per potential opportunities that the event could have occurred.
The correct option is a. Relative occurrence; potential.
A relative frequency is the ratio of the number of times a value of the data occurs in the set of all outcomes to the total number of outcomes.
This can be expressedas fractions, percents, or decimals. When empirical data is collected, such as the number of times a student attends class out of the total classes held, calculating the relative frequency provides a clear illustration of this proportion.
For instance, if we conducted a survey in a class of 20 students and found that 15 attended classes regularly, the relative frequency of regular attendance is 15/20, which can then be converted into a percentage to convey the information more intuitively.
In terms of health statistics, rates such as incidence of disease are often shown as percentages to make small numbers more comprehensible and to clearly show the relative occurrence of the disease in the population.