A study was conducted to find out the concentration of sulphur dioxide in the air in parts 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
(i) Make a grouped frequency distribution table for this data with class intervals as0.00 - 0.04, 0.04 - 0.08, and so on.
(ii) For how many days, was the concentration of sulphur dioxide more than 0.11parts per million?
(i) The data with class interval 0.00-0.04, 0.04-0.08 and so on is represented in the table as:
CONCENTRATION OF SO2 IN AIR (In ppm) | FREQUENCY |
0.00-0.04 | 4 |
0.04-0.08 | 9 |
0.08-0.12 | 9 |
0.12-0.16 | 2 |
0.16-0.20 | 4 |
0.20-0.24 | 2 |
Total | 30 |
(ii) 2 + 4 + 2 = 8
Hence, 8 days have the concentration of sulphur dioxide more than 0.11 parts per million