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:
i) Make a grouped frequency distribution table for this data with class intervals as 0.00 - 0.04, 0.04 - 0.08, and so on.
ii) For how many days, was the concentration of sulphur dioxide more than 0.11 parts per million?
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 |
Solution:
(i) A grouped frequency distribution table with a class size of ‘0.04’ needs to be constructed for the given data.
CONCENTRATION OF SULPHUR DIOXIDE (in ppm) |
NUMBER OF DAYS (frequency) |
0.0 - 0.04 0.04 - 0.08 0.08 - 0.12 0.12 - 0.16 0.16 - 0.20 0.20 - 0.24 |
4 9 9 2 4 2 |
TOTAL |
30 |
(ii) From the above table, we can see that the number of days during which the concentration of sulphur dioxide is more than 0.11 ppm falls over three class intervals, 0.12 - 0.16, 0.16 - 0.20, and 0.20 - 0.24.
So, 2 + 4 + 2 = 8
Thus, 8 days had a concentration of sulphur dioxide more than 0.11 ppm.
Video Solution:
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: i) Make a grouped frequency distribution table for this data with class intervals as 0.00 - 0.04, 0.04 - 0.08, and so on. ii) For how many days was the concentration of sulphur dioxide more than 0.11 parts per million?
NCERT Solutions for Class 9 Maths - Chapter 14 Exercise 14.2 Question 5:
Summary:
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 given. A grouped frequency distribution table for this data with class intervals as 0.00 - 0.04, 0.04 - 0.08 has been created. We have found that 8 days had a concentration of sulphur dioxide more than 0.11 ppm.