Advertisements
Advertisements
प्रश्न
In a sample study of 642 people, it was found that 514 people have a high school certificate. If a person is selected at random, the probability that the person has a high school certificate is ______.
पर्याय
0.5
0.6
0.7
0.8
उत्तर
In a sample study of 642 people, it was found that 514 people have a high school certificate. If a person is selected at random, the probability that the person has a high school certificate is 0.8.
Explanation:
The total number of people in sample study, n(S) = 642.
The number of people who have high school certificate, n(E) = 514.
So, the probability that the person selected has a high school certificate
= `(n(E))/(n(S))`
= `514/642`
= 0.8
Hence, the probability that the person has a high school certificate is 0.8.
APPEARS IN
संबंधित प्रश्न
A teacher wanted to analyse the performance of two sections of students in a mathematics test of 100 marks. Looking at their performances, she found that a few students got under 20 marks and a few got 70 marks or above. So she decided to group them into intervals of varying sizes as follows: 0 − 20, 20 − 30… 60 − 70, 70 − 100. Then she formed the following table:-
Marks | Number of students |
0 - 20 | 7 |
20 - 30 | 10 |
30 - 40 | 10 |
40 - 50 | 20 |
50 - 60 | 20 |
60 - 70 | 15 |
70 - above | 8 |
Total 90 |
(i) Find the probability that a student obtained less than 20 % in the mathematics test.
(ii) Find the probability that a student obtained marks 60 or above.
The distance (in km) of 40 engineers from their residence to their place of work were found as follows.
5 | 3 | 10 | 20 | 25 | 11 | 13 | 7 | 12 | 31 |
19 | 10 | 12 | 17 | 18 | 11 | 32 | 17 | 16 | 2 |
7 | 9 | 7 | 8 | 3 | 5 | 12 | 15 | 18 | 3 |
12 | 14 | 2 | 9 | 6 | 15 | 15 | 7 | 6 | 12 |
What is the empirical probability that an engineer lives:-
(i) less than 7 km from her place of work?What is the empirical probability that an engineer lives:
(ii) more than or equal to 7 km from her place of work?
(iii) within 1/2 km from her place of work?
Three coins are tossed simultaneously 100 times with the following frequencies of different outcomes:
Outcome: | No head | One head | Two heads | Three heads |
Frequency: | 14 | 38 | 36 | 12 |
If the three coins are simultaneously tossed again, compute the probability of:
(i) 2 heads coming up.
(ii) 3 heads coming up.
(iii) at least one head coming up.
(iv) getting more heads than tails.
(v) getting more tails than heads.
The percentage of marks obtained by a student in monthly unit tests are given below:
Unit test: | I | II | III | IV | V |
Percentage of marks obtained: | 69 | 71 | 73 | 68 | 76 |
Find the probability that the student gets:
(i) more than 70% marks
(ii) less than 70% marks
(iii) a distinction
The blood groups of 30 students of class IX are recorded as follows:
A | B | O | O | AB | O | A | O | B | A | O | B | A | O | O |
A | AB | O | A | A | O | O | AB | B | A | O | B | A | B | O |
(i) A
(ii) B
(iii) AB
(iv) O
A big contains 4 white balls and some red balls. If the probability of drawing a white ball from the bag is `2/5`, find the number of red balls in the bag.
what is the probability of getting at least two heads?
Two dice are thrown simultaneously 500 times. Each time the sum of two numbers appearing on their tops is noted and recorded as given in the following table:
Sum | Frequency |
2 | 14 |
3 | 30 |
4 | 42 |
5 | 55 |
6 | 72 |
7 | 75 |
8 | 70 |
9 | 53 |
10 | 46 |
11 | 28 |
12 | 15 |
If the dice are thrown once more, what is the probability of getting a sum between 8 and 12?
Bulbs are packed in cartons each containing 40 bulbs. Seven hundred cartons were examined for defective bulbs and the results are given in the following table:
Number of defective bulbs | 0 | 1 | 2 | 3 | 4 | 5 | 6 | more than 6 |
Frequency | 400 | 180 | 48 | 41 | 18 | 8 | 3 | 2 |
One carton was selected at random. What is the probability that it has defective bulbs from 2 to 6?
Over the past 200 working days, the number of defective parts produced by a machine is given in the following table:
Number of defective parts |
0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 |
Days | 50 | 32 | 22 | 18 | 12 | 12 | 10 | 10 | 10 | 8 | 6 | 6 | 2 | 2 |
Determine the probability that tomorrow’s output will have more than 13 defective parts