The following is the distribution of height of students of certain class in a certain city:


Height (in cms):



160-162



163-165



166-168



169-171



172-174



No. of students:



15



118



142



127



18



Find the average height of maximum number of students.


Height(exclusive)



10-162



163-165



166-168



169-171



172-174



Height(inclusive)



159.5-162.5



162.5-165.5



165.5-168.5



168.5-171.5



171.5-174.5



No. of students



15



118



142



127



18



Here, the maximum frequency is 142, the corresponding class interval 165.5-168.5 is modal class


l=165.5, h=3, f=142, f1=118, f2 =127


Mode = l +


= 165.5 +


=18+ =165.5 +1.85


=167.35 cm


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