Question

To find concentration (part per million) of (SO₂) Sulphur dioxide in air data is collected from 30 colonies of a city which are given below:

Concentration of SO2(ppm)	0.00-0.04	0.04-0.08	0.08-0.12	0.12-0.16	0.16-0.20	0.20-0.24
Frequency	4	9	9	2	4	2

Find mean of concentration of SO₂ in Air.

Answer 1

Arithmetic mean (\(\overline { x }\)) = \(\frac { { \Sigma f }_{ i }{ d }_{ i } }{ { \Sigma f }_{ i } } \) = \(\frac { 2.96 }{ 30 }\) 

= 0.0986 or 0.099 (approx)

Thus, mean of concentration of SO₂ in Air = 0.099 part per million.