Final answer:
The relative frequency is calculated by dividing the frequency of a specific data value by the total number of data values. Cumulative relative frequency adds up the relative frequencies up to the current class.
Step-by-step explanation:
The relative frequency of a class is computed by dividing the frequency of a particular data value by the total number of data values in a sample. For instance, if a survey in the class finds that there are three students who work two hours, and the total number of students in the sample is 20, the relative frequency for students working two hours would be 3/20 or 0.15. This method can be applied to calculate both simple relative frequencies and cumulative relative frequencies individually for each class, or value, of the data set.
To calculate cumulative relative frequency, one should add the relative frequencies of all the classes that come before it, plus the relative frequency of the current class. This process is useful in determining the proportion of data values that fall within certain ranges.