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प्रश्न
The marks of 20 students in a test were as follows:
2, 6, 8, 9, 10, 11, 11, 12, 13, 13, 14, 14, 15, 15, 15, 16, 16, 18, 19 and 20.
Calculate:
- the mean
- the median
- the mode
उत्तर
Arranging the terms in ascending order:
2, 6, 8, 9, 10, 11, 11, 12, 13, 13, 14, 14, 15, 15, 15, 16, 16, 18, 19, 20
Number of terms = 20
Σx = 2 + 6 + 8 + 9 + 10 + 11 + 11 + 12 + 13 + 13 + 14 + 14 + 15 + 15 + 15 + 16 + 16 + 18 + 19 + 20 = 257
i. Mean = `(∑x)/(∑n) = 257/20 = 12.85`
ii. Median = `(10^(th) term + 11^(th) term)/2`
= `(13 + 14)/2`
= `27/2`
= 13.5
iii. Mode = 15 as it has maximum frequencies i.e. 3
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संबंधित प्रश्न
The median is always one of the numbers in a data.
Calculate the mean of the following distribution :
| Class Interval | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 | 50-60 |
| Frequency | 8 | 5 | 12 | 35 | 24 | 16 |
If the mean of the following observations is 54, find the value of p.
| Class | 0 – 20 | 20 – 40 | 40 – 60 | 60 – 80 | 80 – 100 |
| Frequency | 7 | p | 10 | 9 | 13 |
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.
A mathematics aptitude test of 50 students was recored as follows:
| Marks | No. of students |
| 50-60 | 4 |
| 60-70 | 8 |
| 70-80 | 14 |
| 80-90 | 19 |
| 90-100 | 5 |
Draw a histrogram for the above data using a graph paper and locate the mode.
The percentage marks obtained in 10 subjects by a student are 84, 88, 72, 91, 68, 75, 98, 96, 79 and 86. Find the median of the marks obtained.
Find the mean of 53, 61, 60, 67 and 64.
Find the mean of: 3, 1, 5, 4, 4 and 7
Find the mean of 35, 44, 31, 57, 38, 29, 26,36, 41 and 43.
Which of the following has the same mean, median and mode?
