Given below is the frequency distribution table regarding the concentration of sulphur dioxide in the air in parts per million of a certain city for 30 days.
Conc. Of SO2 | 0.00-0.04 | 0.04-0.08 | 0.08-0.12 | 0.12-0.16 | 0.16-0.20 | 0.20-0.24 |
No. of days | 4 | 8 | 9 | 2 | 4 | 3 |
Find the probability of concentration of sulphur dioxide in the interval 0.12-0.16 on any of these days.
Given,
The frequency distribution table regarding the concentration of sulphur dioxide in the air in parts per million of a certain city for 30 days
Total number of days = 30
Probability of concentration of SO2 in the interval 0.12 – 0.16 is
= 
11