**Frequency distribution table shows concentration of sulphur dioxide in the air in parts per million of a certain city for 30 days.**

**Find the probability of the concentration of sulphur dioxide in the interval 0.12 - 0.16 on any of these days.**

**Answer:**

Let E be the event that concentration of sulphur dioxide is in the interval 0.12-0.16 on any of the 30 days.

**P(E) =** (Number of days for which concentration of is in the interval 0.12-0.16 from 30 days / Total number of days)