To check the quality of two brands of light bulbs

[prasanna]

To check the quality of two brands of light bulbs, their life in burning hours was estimated as under for 100 bulbs of each brand.

(i) Which brand gives higher life? (ii) Which brand is more dependable?

[prasanna]

(i) The average life of bulb of brand B is comparatively higher than that of brand A.
(ii) The bulbs of brand B are more dependable as CV of brand B is lesser than CV of brand A.