Advertisements
Advertisements
प्रश्न
Find the mean of the following frequency distribution :
| Class | 1-10 | 11-20 | 21-30 | 31-40 | 41-50 |
| Frequency | 9 | 12 | 15 | 10 | 14 |
उत्तर
| Class Interval | xi | fi | fixi |
| 1-10 | 5.5 | 9 | 49.5 |
| 11-20 | 15.5 | 12 | 186 |
| 21-30 | 25.5 | 15 | 382.5 |
| 31-40 | 35.5 | 10 | 355 |
| 41-50 | 45.5 | 14 | 637 |
| Total | 60 | 1610 |
`barx = (Σf_iX_i)/(Σ"f")`
`barx = 1610/60`
`barx = 26.83`
∴ Mean = 26.83
APPEARS IN
संबंधित प्रश्न
The following table gives the weekly wages of workers in a factory.
| Weekly wages (Rs) | No. of workers |
| 50 – 55 | 5 |
| 55 – 60 | 20 |
| 60 – 65 | 10 |
| 65 – 70 | 10 |
| 70 – 75 | 9 |
| 75 – 80 | 6 |
| 80 – 85 | 12 |
| 85 – 90 | 8 |
Calculate the mean by using:
Short-cut method
Find the mean of first 10 prime numbers.
Draw a histogram for the following distribution and estimate the mode:
| Marks | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 | 50-60 | 60-70 | 70-80 |
| No. of students | 3 | 7 | 15 | 24 | 16 | 8 | 5 | 2 |
Draw a histogram for the following distribution and estimate the mode:
| Mangoes | 0-9 | 10-19 | 20-29 | 30-39 | 40-49 | 50-59 |
| No. of trees | 10 | 16 | 20 | 14 | 6 | 4 |
The weights of 11 students in a class are 36 kg, 45 kg, 44 kg, 37 kg, 36 kg, 41 kg, 45 kg, 43 kg, 39 kg, 42 kg and 40 kg. Find the median of their weights.
The marks obtained by 200 students in an examination are given below :
| Marks | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 | 50-60 | 60-70 | 70-80 | 80-90 | 90-100 |
| No.of students | 5 | 10 | 11 | 20 | 27 | 38 | 40 | 29 | 14 | 6 |
Using a graph paper, draw an Ogive for the above distribution. Use your Ogive to estimate:
(i) the median;
(ii) the lower quartile;
(iii) the number of students who obtained more than 80% marks in the examination and
(iv) the number of students who did not pass, if the pass percentage was 35.
Use the scale as 2 cm = 10 marks on one axis and 2 cm = 20 students on the other axis.
Estimate the median, the lower quartile and the upper quartile of the following frequency distribution by drawing an ogive:
| Class Interval | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 | 50-60 | 60-70 |
| Frequency | 4 | 12 | 21 | 18 | 15 | 7 | 3 |
Find the mean and the median of: 5, 8, 10, 11,13, 16, 19 and 20
The median of the data: 3, 4, 5, 6, 7, 3, 4 is ______.
Median of the data may or may not be from the given data.
