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प्रश्न
A boy scored following marks in various class tests during a term; each test being marked out of 20.
15, 17, 16, 7, 10, 12, 14, 16, 19, 12 and 16
What are his mean marks?
उत्तर
Arranging the given data in ascending order:
7, 10, 12, 12, 14, 15, 16, 16, 16, 17, 19
Mean `(barx) = (x_1 + x_2 + x_3 + ....... + x_n)/n`
= `154/11`
= 14
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संबंधित प्रश्न
Calculate the mean of the following distribution using step deviation method.
| Marks | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 | 50-60 |
| Number of students |
10 | 9 | 25 | 0 | 16 | 10 |
In a school, 100 pupils have heights as tabulate below:
| Height (in cm) | No. of pupils |
| 121 – 130 | 12 |
| 131 – 140 | 16 |
| 141 – 150 | 30 |
| 151 – 160 | 20 |
| 161 – 170 | 14 |
| 171 – 180 | 8 |
Find the median height by drawing an ogive.
Attempt this question on graph paper.
| Age (yrs ) | 5-15 | 15-25 | 25-35 | 35-45 | 45-55 | 55-65 | 65-75 |
| No.of casualties | 6 | 10 | 15 | 13 | 24 | 8 | 7 |
(1) Construct the 'less than' Cumulative frequency curve for the above data. using 2 cm =10 years on one axis and 2 cm =10 casualties on the other.
(2)From your graph determine :
(a)the median
(b)the lower quartile
Using a graph paper, draw an ogive for the following distribution which shows a record of the width in kilograms of 200 students.
| Weight | Frequency |
| 40 – 45 | 5 |
| 45 – 50 | 17 |
| 50 – 55 | 22 |
| 55 – 60 | 45 |
| 60 – 65 | 51 |
| 65 – 70 | 31 |
| 70 – 75 | 20 |
| 75 – 80 | 9 |
Use your ogive to estimate the following:
- The percentage of student weighting 55 kg or more
- The weight above which the heaviest 30% of the student fall
- The number of students who are
- underweight
- overweight, If 55.70 kg is considered as standard weight.
Following 10 observations are arranged in ascending order as follows.
2, 3, 5, 9, x + 1, x + 3, 14, 16, 19, 20
If the median of the data is 11, find the value of x.
Find the mean of the following frequency distribution :
| Class | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 |
| Frequency | 4 | 7 | 6 | 3 | 5 |
Find the mean of the following frequency distribution :
| Class | 101-110 | 111-120 | 121-130 | 131-140 | 141-150 | 151-160 |
| Frequency | 11 | 16 | 20 | 30 | 14 | 9 |
Estimate the median, the lower quartile and the upper quartile of the following frequency distribution by drawing an ogive:
| Marks(more than) | 90 | 80 | 70 | 60 | 50 | 40 | 30 | 20 | 10 | 0 |
| No. of students | 6 | 13 | 22 | 34 | 48 | 60 | 70 | 78 | 80 | 80 |
Find the mean of: 7, 10, 4 and 17
The median first 6 odd natural numbers is ____________
