|
(d) Class frequency
Ans. The number of observations corresponding
to a particular class is known as the frequency of
that class or the class frequency. In the following
illustration, the frequency of the class (10-20) is
3 and (20-30) is 5.
|
Marks
|
Class frequency |
| 10-20 |
3 |
| 20-30 |
5 |
(e) Class mid-point or class mark
Ans. It is the value lying half way between
the lower and upper class limits of a class-interval.
Mid-point of a class is calculated as follows:
|
Upper limit of the class
+ Lower limit of the class
|
| Mid-point of a class = |
|
|
2
|
(f) Relative Frequency
Ans. The relative frequency of a class is defined
as the frequency of that class divided by the total
number of measurements (the total frequency).
Relative frequency = (fi/n) for class i
Where:
fi = frequency of class i where i represents any of
the classes
n = the total number of measurements
(g) Pie Chart
Ans. Pie Chart is used to show the break up of
a total into component parts. It is used to represent
the division of a sum of money into its components.
|
