Q8 of 40 Page 200

The electricity bills (in rupees) of 25 houses in a locality are given below. Construct a grouped frequency distribution table with a class size of 75.

170, 212, 252, 225, 310, 712, 412, 425, 322, 325, 192, 198, 230, 320, 412, 530, 602, 724, 370, 402, 317, 403, 405, 372, 413


Given are electricity bills (in rupees) of 25 houses in locality.

To construct a grouped frequency distribution table with a class size of 75, note down smallest and largest number from the data.


Smallest number = 170


Largest number = 724


So, let the class interval start from 150.


Then, add 75 to 150 = 150 + 75 = 225


⇒ First class interval = 150-225


Similarly,


Second class interval = 225-300 [∵, 225 + 75 = 300]


And so on…


For frequencies, count the occurrence of the numbers lying between the particular class interval.


Let us construct a table in order to show these class intervals along with their frequencies.



Thus, this is the required frequency distribution table.


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