Advertisements
Advertisements
प्रश्न
If the mean of the following distribution is 27, find the value of p.
| Class | 0 - 10 | 10 - 20 | 20 - 30 | 30 - 40 | 40 - 50 |
| Frequency | 8 | p | 12 | 13 | 10 |
उत्तर
| Class interval | Mid value(x1) | Frequency(f1) | f1x1 |
| 0 - 10 | 5 | 8 | 40 |
| 10 - 20 | 15 | p | 15p |
| 20 - 30 | 25 | 12 | 300 |
| 30 - 40 | 35 | 13 | 455 |
| 40 - 50 | 45 | 10 | 450 |
| N = 43 + p | `sumf_1x_1=1245 + 15p` |
Given
Mean = 27
`rArr(sumf_1x_1)/N=27`
`rArr(1245 + 15p)/(43+p)=27`
1245 + 15p = 27(43 + p)
1245 + 15p = 27p + 1161
27p - 15p = 1245 - 1161
12p = 84
p = 84/12 = 7
APPEARS IN
संबंधित प्रश्न
The measurements (in mm) of the diameters of the head of the screws are given below:
| Diameter (in mm) | No. of Screws |
| 33 — 35 | 10 |
| 36 — 38 | 19 |
| 39 — 41 | 23 |
| 42 — 44 | 21 |
| 45 — 47 | 27 |
Calculate mean diameter of head of a screw by ‘Assumed Mean Method’.
Consider the following distribution of daily wages of 50 worker of a factory.
|
Daily wages (in Rs) |
100 − 120 |
120 − 140 |
140 −1 60 |
160 − 180 |
180 − 200 |
|
Number of workers |
12 |
14 |
8 |
6 |
10 |
Find the mean daily wages of the workers of the factory by using an appropriate method.
The following distribution gives the number of accidents met by 160 workers in a factory during a month.
| No. of accidents(x) | 0 | 1 | 2 | 3 | 4 |
| No. of workers (f) | 70 | 52 | 34 | 3 | 1 |
Find the average number of accidents per worker.
Find the mean of each of the following frequency distributions
| Class interval | 0 - 6 | 6 - 12 | 12 - 18 | 18 - 24 | 24 - 30 |
| Frequency | 7 | 5 | 10 | 12 | 6 |
Find the mean of the following frequency distribution, using the assumed-mean method:
| Class | 100 – 120 | 120 – 140 | 140 – 160 | 160 – 180 | 180 – 200 |
| Frequency | 10 | 20 | 30 | 15 | 5 |
The average score of boys in an examination of a school is 71 and of girls is 73. The averages score of school in that examination is 71.8. Find the ratio of the number of boys between number of girls appeared in the examination.
Find the mean of the following distribution:
| x | 4 | 6 | 9 | 10 | 15 |
| f | 5 | 10 | 10 | 7 | 8 |
In the formula `barx = a + h((sumf_iu_i)/(sumf_i))`, for finding the mean of grouped frequency distribution, ui = ______.
Find the mean for the following distribution:
| Class Interval | 20 - 40 | 40 - 60 | 60 - 80 | 80 - 100 |
| Frequency | 4 | 7 | 6 | 3 |
The following table gives the marks scored by a set of students in an examination. Calculate the mean of the distribution by using the short cut method.
| Marks | Number of Students (f) |
| 0 – 10 | 3 |
| 10 – 20 | 8 |
| 20 – 30 | 14 |
| 30 – 40 | 9 |
| 40 – 50 | 4 |
| 50 – 60 | 2 |
