Organisation of Data Test - 7

To convert the inclusive series into exclusive series, we can use following steps :
(i) First, we find the difference of the upper limit of class interval and the lower limit of the next class interval
(ii) Half of that difference is added to the upper limit of class interval and half is subtracted from the lower limit of the class interval.

When the mid-values of class-intervals are given the class-intervals are found by first finding out the difference between two mid-values and then subtracting half of it from each mid-value to find the lower limit and adding it to each mid-value to find the upper limit of the class-intervals.

Mid point of a class interval can be obtained by adding lower class and upper class and dividing by 2.

The Range is the difference between the lowest and highest values. 

0-3, implies no.of all students obtaining marks below 3 but greater than 0. Similarly, for other class greater than 3 but less than 6. 

The mid-points of class-intervals of various class group are called mid-values. MV= (Lower limit + Upper limit) /2

If, in a frequency distribution, the initial class interval is indeterminate at its beginning and/or the final class interval is indeterminate at its end, the distribution is said to possess “open ended” classes.

The total frequencies of a particular class and all classes prior to that particular class is called the Less than type cumulative frequency of that class or simply the Cumulative frequency of that class. Here the no of workers who got wages below 109 equals 5+9=14

The cumulative frequency of a particular class and all the classes after that class is called the "greater than" type cumulative frequency.  Here we take the frequency of the class 100 onwards ie., 9+3=12

Class interval refers to the numerical width of any class in a particular distribution. Mathematically it is defined as the difference between the upper class limit and the lower class limit.

Class Interval= Upper Class limit – Lower class limit