Advertisements
Advertisements
प्रश्न
Construct a frequency polygon without using a histogram for the following frequency distribution :
| Class Interval | 1-10 | 11-20 | 21-30 | 31-40 | 41-50 |
| Frequency | 8 | 12 | 10 | 16 | 6 |
Advertisements
उत्तर
Steps :
1. Make the class intervals continuous by subtracting 0.5 from the lower limit of each class and add 0.5 to the upper limit of each class .
2. Find class mark by calculating the average of the class interval.
3. On the x-axis , take 1 cm as 5 units and plot class interval.
4. On the y-axis , take 1 cm as 5 units and plot frequency.
5. Plot the points on the graph. (5.5,8),(15.5,12),(25.5,10),(35.5,16),(45.5,6).
6. Mark two more midpoints of zero frequency on x-axis at the start and at the end.
7. Now connect the points using straight lines.
| Class Interval | Class Mark | Frequency |
| 0.5-10.5 | = `(0.5+10.5)/2 = 5.5` | 8 |
| 10.5-20.5 | = `(10.5+20.5)/2 = 15.5` | 12 |
| 20.5-30.5 | = `(20.5 + 30.5)/2 = 25.5` | 10 |
| 30.5-40.5 | = `(30.5 + 40.5)/2 = 35.5` | 16 |
| 40.5-50.5 | = `(40.5 + 50.5)/2 = 45.5` | 6 |
APPEARS IN
संबंधित प्रश्न
The following table shows the investment made by some families. Show
the information by a histogran.
| Investment (Thousand Rupees) |
10-15 | 15-20 | 20-25 | 25-30 | 30-35 |
| No. of families | 30 | 50 | 60 | 55 | 15 |
Construct a histogram for the following data:
| Monthly school fee (in Rs): | 30−60 | 60−90 | 90−120 | 120−150 | 150−180 | 180−210 | 210−240 |
| Number of schools: | 5 | 12 | 14 | 18 | 10 | 9 | 4 |
The weekly wages (in Rs.) of 30 workers in a factory are given:
830, 835, 890, 810, 835, 836, 869, 845, 898, 890, 820, 860, 832, 833, 855, 845, 804, 808, 812, 840, 885, 835, 835, 836, 878, 840, 868, 890, 806, 840
Mark a frequency table with intervals as 800-810, 810-820 and so on, using tally marks. Also, draw a histogram and answer the following questions:
(i) Which group has the maximum number of workers?
(ii) How many workers earn Rs 850 and more?
(iii) How many workers earn less than Rs 850?
Find the lower quartile, the upper quartile, the interquartile range and the semi-interquartile range for the following frequency distributions:
| Marks | 25 | 30 | 35 | 40 | 45 | 50 |
| No. of students | 6 | 15 | 12 | 10 | 18 | 9 |
Construct histograms for following frequency distribution:
| Class Interval | 1-10 | 11-20 | 21-30 | 31-40 | 41-50 |
| Frequency | 11 | 23 | 30 | 20 | 16 |
Identify the following data can be represented in a histogram?
Production of cycles in different years
Form a continuous frequency distribution table and draw histogram from the following data.
| Age (in years) | No. of persons |
| Under 5 | 1 |
| Under 10 | 12 |
| Under 15 | 19 |
| Under 20 | 26 |
| Under 25 | 27 |
| Under 30 | 35 |
| Under 35 | 38 |
| Under 40 | 45 |
| Under 45 | 48 |
| Under 50 | 53 |
In a histogram ______ are drawn with width equal to a class interval without leaving any gap in between.
Look at the histogram below and answer the questions that follow.
- How many students have height more than or equal to 135 cm but less than 150 cm?
- Which class interval has the least number of students?
- What is the class size?
- How many students have height less than 140 cm?
Use graph paper for this question. Estimate the mode of the given distribution by plotting a histogram. [Take 2 cm = 10 marks along one axis and 2 cm = 5 students along the other axis]
| Daily wages (in ₹) | 30 - 40 | 40 - 50 | 50 - 60 | 60 - 70 | 70 - 80 |
| No. of Workers | 6 | 12 | 20 | 15 | 9 |
