Question

Answer in detail

Explain various technical terms, important for frequency distribution.

Answer 1

The following are the various technical terms used for frequency distribution:
i. Class: It refers to the group or section that divides a variable into parts to form a set of the given frequency.
ii. Class-limit: It refers to the extreme values of the classes. Every class has a minimum value known as the lower limit and maximum value known as the upper limit.
iii. Class-mark: The mid-value of a class interval is known as the midpoint (or class mark) of that class interval. For example, if the class is 50-100 then,
Class-mark $=\frac{50+100}{2}=75$
iv. Class-interval: The difference between the upper and lower limits of a class is known as class interval or class-boundary. For example, for the class 20-40, the class interval is 20.
v. Tally marks: Tally marks are used in organising and presenting data in a uniform manner. Generally, tally marks are arranged in groups of five. For every observation, a vertical bar is drawn and after the fourth bar, all the bars are struck across to represent the fifth or five observations.
vi. Class-frequency- It refers to the number of observations included in a particular class.
vii. Total frequency- The sum or the aggregate of all the frequencies is known as total frequency.