In the table given below, the times taken by 120 athletes to run a 100 - m - hurdle race are given.


Class



13.8 - 14



14 - 14.2



14.2 - 14.4



14.4 - 14.6



14.6 - 14.8



14.8 - 15



Frequency



2



4



15



54



25



20



Find the number of athletes who completed the race in less than 14.6 seconds.

We need to form a ‘less than type’ table to solve this.


CLASS



FREQUENCY



CUMULATIVE FREQUENCY (Cf)



Less than 14



2



2



Less than 14.2



4



2 + 4 = 6



Less than 14.4



15



6 + 15 = 21



Less than 14.6



54



21 + 54 = 75



Less than 14.8



25



75 + 25 = 100



Less than 15



20



100 + 20 = 120



Here, cumulative frequency shows number of athletes taking different time intervals to run a 100 - m - hurdle race.


So by the table, there are 75 athletes who completed the race in less than 14.6 seconds.


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