The following distribution gives the number of accidents met by 160 workers in a factory during a month.


No. of accidents (x):



0



1



2



3



4



No. of workers (f):



70



52



34



3



1



Find the average number of accidents per worker.

Let the assumed mean (A) = 2


No. of accidents (xi)



No. of workers (fi)



ui = xi – A = xi - 2



fiui



0



70



-2



-140



1



52



-1



-52



2



34



0



0



3



3



1



3



4



1



2



2




N = 160




fiui = -187



Average number of accidents per day workers = A +


= 2 + =


= 0.83


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