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प्रश्न
To know the opinion of the students about Mathematics, a survey of 200 students was conducted. The data is recorded in the following table:
| Opinion: | Like | Dislike |
| Number of students: | 135 | 65 |
Find the probability that a student chosen at random (i) likes Mathematics (ii) does not like it.
उत्तर
The total number of trials is 200.
Remember the empirical or experimental or observed frequency approach to probability.
If n be the total number of trials of an experiment and A is an event associated to it such that A happens in m-trials. Then the empirical probability of happening of event A is denoted by P (A) and is given by
P (A) =`m/n`
(i) Let A be the event of liking mathematics.
The number of times A happens is 135.
Therefore, we have
P (A) =`135/200`
= 0.675
(ii) Let B be the event of disliking mathematics.
The number of times B happens is 65.
Therefore, we have
P (B) =`65/200`
= 0.325
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संबंधित प्रश्न
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| Frequency | 23 | 72 | 77 | 28 |
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An organization selected 2400 families at random and surveyed them to determine a relationship between income level and the number of vehicles in a family. The information gathered is listed in the table below:-
|
Monthly income (in Rs.) |
Vehicles per family | |||
| 0 | 1 | 2 | Above 2 | |
| Less than 7000 | 10 | 160 | 25 | 0 |
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| 13000 – 16000 | 2 | 469 | 59 | 25 |
| 16000 or more | 1 | 579 | 82 | 88 |
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(iv) earning Rs 13000 − 16000 per month and owning more than 2 vehicles.
(v) owning not more than 1 vehicle.
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| A | 9 |
| B | 6 |
| AB | 3 |
| O | 12 |
| Total | 30 |
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