Q. 5. A study was conducted to find out the concentration of sulphur dioxide in the air inparts per million (ppm) of a certain city. The data obtained for 30 days is as follows:
0.03 0.08 0.08 0.09 0.04 0.17
0.16 0.05 0.02 0.06 0.18 0.20
0.11 0.08 0.12 0.13 0.22 0.07
0.08 0.01 0.10 0.06 0.09 0.18
0.11 0.07 0.05 0.07 0.01 0.04
(ii) For how many days, was the concentration of sulphur dioxide more than 0.11 parts per million?
From the frequency distribution table, we can see the concentration of sulphur dioxide was more than 0.11 ppm for 8 days.
It was in the range 0.12 - 0.16 for 2 days, 0.16 - 0.20 for 4 days and 0.20 - 0.24 for 2 days.