Sample of polythene bags from a manufacturer are tested by a buyer for bursting pressure with the following data :

Question

Bursting Pressure (in lbs) :	5-9	9-13	13-17	17-21	21-25	25-29	29-33
No. of bags :	2	4	9	12	6	4	3

 

Calculate : (i) the standard deviation and (ii) the coefficient of variation.

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