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In Q.5, Exercise 14.2, you were asked to prepare a frequency distribution table, regarding the concentration of sulphur dioxide in the air in parts per million of a certain city for 30 days. Using the table, find the probability of the concentration of sulphur dioxide in the interval 0.12 – 0.16 on any of these days.
Solution:
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 |
The probability of certain event is given by the ratio of occurrence of a particular event by the total number of events.
Probability of an event, P(E) = Number of instances that event takes place/Total number of instances
Total number of days = 30
Number of days on which concentration of sulphur dioxide was in the interval 0.12 – 0.16 = 2
Probability of the concentration of Sulphur dioxide in the interval 0.12 – 0.16 = 2/30 = 1/15
☛ Check: Class 9 Maths NCERT Solutions Chapter 15
Video Solution:
In Q.5, Exercise 14.2, you were asked to prepare a frequency distribution table, regarding the concentration of sulphur dioxide in the air in parts per million of a certain city for 30 days. Using the table, find the probability of the concentration of sulphur dioxide in the interval 0.12 – 0.16 on any of these days.
NCERT Solutions for Class 9 Maths Chapter 15 Exercise 15.1 Question 12
Summary:
We have found that the number of days on which concentration was in the interval 0.12 – 0.16 = 2 and the probability of the concentration of Sulphur dioxide in the interval 0.12 – 0.16 = 2/30 = 1/15.
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