The relative frequency of a class in a histogram is computed by

A) dividing the frequency of the class by the number of classes.
B) dividing the frequency of the class by the class width.
C) dividing the frequency of the class by the total of all frequencies.
D) None of these choices.

The relative frequency of a class in a histogram is computed by dividing the frequency of the class by the total of all frequencies. This provides a proportion or percentage of the total amount of data that falls into that specific class. Dividing by the number of classes or the class width would not accurately represent the proportion of that specific class within the entire dataset. Therefore, option C is the correct choice.