Class Mark


 
 
Concept Explanation
 

Class Mark

Class Mark:

It is equal to half of the sum of the lower and upper limits of a class or we can say that the number in the middle of the class interval is the class mark. It is found by adding the upper and lower limits and dividing by two .It can also be found by  adding the upper and boundaries and dividing by two .

Illustration: Find the class mark for the interval 31-40

Solution:

     The class mark can be found by dividing the sum of upper limit and the lower limit of the class

upper limit = 40

lower limit = 31

 So class mark =

   frac{upper;;limit+lower;;limit}{2}=frac{31+40}{2}=frac{71}{2}=35.5

Sample Questions
(More Questions for each concept available in Login)
Question : 1

Find the class mark with minimum frequency by using the given data:

Class SizeFrequency
20-408
40-604
60-807
80-1009
100-1202
Total32

 

Right Option : D
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Explanation
Question : 2

The mid-point of a class interval is called its __________________.

Right Option : B
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Explanation
Question : 3

In a city, the weekly observations on the cost of living index made in a study are given in the following table : 

Cost of living index148 - 158158 - 168 168 - 178
No. of weeks5209

What is the class mark of interval 158 - 168 ?

Right Option : D
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Explanation
 
 


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