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प्रश्न
Construct a frequency polygon for the following data:
| Class-Intervals | 10 - 14 | 15 - 19 | 20 - 24 | 25 - 29 | 30 - 34 |
| Frequency | 5 | 8 | 12 | 9 | 4 |
उत्तर
The class intervals are inclusive. We will first convert them into the exclusive form.
| Class-Interval | Frequency |
| 9.5 - 14.5 | 5 |
| 14.5 - 19.5 | 8 |
| 19.5 - 24.5 | 12 |
| 24.5 - 29.5 | 9 |
| 29.5 - 34.5 | 4 |
Steps:
- Draw a histogram for the given data.
- Mark the mid-point at the top of each rectangle of the histogram drawn.
- Also, mark the mid-point of the immediately lower class-interval and mid-point of the immediately higher class-interval.
- Join the consecutive mid-points marked by straight lines to obtain the required frequency polygon.
The required frequency polygon is as follows:
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संबंधित प्रश्न
The length of 40 leaves of a plant are measured correct to one millimetre, and the obtained data is represented in the following table:-
| Length (in mm) | Number of leaves |
| 118 - 126 | 3 |
| 127 - 135 | 5 |
| 136 - 144 | 9 |
| 145 - 153 | 12 |
| 154 - 162 | 5 |
| 163 - 171 | 4 |
| 172 - 180 | 2 |
- Draw a histogram to represent the given data. [Hint: First make the class intervals continuous]
- Is there any other suitable graphical representation for the same data?
- Is it correct to conclude that the maximum number of leaves are 153 mm long? Why?
Study the bar graph representing the number of persons in various age groups in a town shown in Fig. below. Observe the bar graph and answer the following questions:
(i) What is the percentage of the youngest age-group persons over those in the oldest age group?
(ii) What is the total population of the town?
(iii) What is the number of persons in the age group 60 - 65?
(iv) How many persons are more in the age-group 10 - 15 than in the age group 30 - 35?
(v) What is the age-group of exactly 1200 persons living in the town?
(vi) What is the total number of persons living in the town in the age-group 50 - 55?
(vii) What is the total number of persons living in the town in the age-groups 10 - 15 and 60 - 65?
(viii) Whether the population in general increases, decreases or remains constant with the increase in the age-group.
The following table shows the interest paid by a company (in lakhs):
| Year | 1995-96 | 1996-97 | 1997-98 | 1998-99 | 1999-2000 |
| Interest (in lakhs of rupees | 20 | 25 | 15 | 18 | 30 |
Draw the bar graph to represent the above information.
Draw, in the same diagram, a histogram and a frequency polygon to represent the following data which shows the monthly cost of living index of a city in a period of 2 years:
| Cost of living index: |
440-460 | 460-480 | 480-500 | 500-520 | 520-540 | 540-560 | 560-580 | 580-600 |
| No. of months: | 2 | 4 | 3 | 5 | 3 | 2 | 1 | 4 |
Draw a histogram for the daily earnings of 30 drug stores in the following table:
| Daily earning (in Rs): |
450-500 | 500-550 | 550-600 | 600-650 | 650-700 |
| Number of Stores: | 16 | 10 | 7 | 3 | 1 |
Read the following bar graph and answer the following questions:
a. What information is given by the graph?
b. Which state is the largest producer of wheat?
c. Which state is the largest producer of sugar?
d. Which state has total production of wheat and sugar as its maximum?
e. Which state has the total production of wheat and sugar minimum?
In a diagnostic test in mathematics given to students, the following marks (out of 100) are recorded:
46, 52, 48, 11, 41, 62, 54, 53, 96, 40, 98, 44
Which ‘average’ will be a good representative of the above data and why?
Expenditure on Education of a country during a five year period (2002-2006), in crores of rupees, is given below:
| Elementary education | 240 |
| Secondary Education | 120 |
| University Education | 190 |
| Teacher’s Training | 20 |
| Social Education | 10 |
| Other Educational Programmes | 115 |
| Cultural programmes | 25 |
| Technical Education | 125 |
Represent the information above by a bar graph.
Draw a histogram of the following distribution:
| Heights (in cm) | Number of students |
| 150 – 153 | 7 |
| 153 – 156 | 8 |
| 156 – 159 | 14 |
| 159 – 162 | 10 |
| 162 – 165 | 6 |
| 165 – 168 | 5 |
Draw a histogram to represent the following grouped frequency distribution:
| Ages (in years) | Number of teachers |
| 20 – 24 | 10 |
| 25 – 29 | 28 |
| 30 – 34 | 32 |
| 35 – 39 | 48 |
| 40 – 44 | 50 |
| 45 – 49 | 35 |
| 50 – 54 | 12 |
