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प्रश्न
The following is the distribution of total household expenditure (in Rs.) of manual worker in a city:
| Expenditure (in Rs): |
100-150 | 150-200 | 200-250 | 250-300 | 300-350 | 350-400 | 400-450 | 450-500 |
| No. of manual workers: | 25 | 40 | 33 | 28 | 30 | 22 | 16 | 8 |
Draw a histogram and a frequency polygon representing the above data.
उत्तर
To represent the given data by a histogram, we first draw horizontal and vertical axes. Let us consider that the horizontal and vertical axes represent the class-limits and the frequencies of the class-intervals respectively.
The given data is a continuous grouped frequency distribution with equal class-intervals. Construct rectangles with class-intervals as bases and respective frequencies as heights. It should be noted that the scale for horizontal axis may not be same as the scale for vertical axis. To draw the frequency polygon of the given data using histogram, obtain the mid-points of the upper horizontal side of each rectangle and then join these mid-points of the adjacent rectangles of the histogram by line segments. Obtain the mid-points of two class-intervals of 0 frequencies, i.e. on the horizontal axis, one adjacent to the first, on its left and one adjacent to the last, on its right. These class-intervals are known as imagined class-intervals. Complete the polygon by joining the mid-points of first and last class-intervals to the mid-points of imagined class-intervals adjacent to them. Let us take one vertical division is equal to 5 workers.
The heights of the different rectangles are as follows:
1. The height of the rectangle corresponding to the class-interval 100-150 is `25/5=5` big divisions.
2. The height of the rectangle corresponding to the class-interval 150-200 is `40/5=8` big divisions.
3. The height of the rectangle corresponding to the class-interval 200-250 is ` 33/5 = 6.6` big divisions.
4. The height of the rectangle corresponding to the class-interval 250-300 is `28/5 = 5.6 ` big divisions.
5. The height of the rectangle corresponding to the class-interval 300-350 is ` 30/5 =6 ` big divisions.
6. The height of the rectangle corresponding to the class-interval 350-400 is ` 22/5 = 4.4` big divisions.
7. The height of the rectangle corresponding to the class-interval 400-450 is ` 16/5 = 3.2` big division.
8. The height of the rectangle corresponding to the class-interval 450-500 is ` 8/5 = 1.6` big divisions.
The histogram of the given data is as follows:
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संबंधित प्रश्न
Read the bar graph shown in Fig. 23.10 and answer the following questions
(i) What is the information given by the bar graph?
(ii) What was the number of commercial banks in 1977?
(iii) What is the ratio of the number of commercial banks in 1969 to that in 1980?
(iv) State whether true or false:
The number of commercial banks in 1983 is less than double the number of commercial banks in 1969.
Given below (Fig. below) is the bar graph indicating the marks obtained out of 50 in mathematics paper by 100 students. Read the bar graph and answer the following questions:
(i) It is decided to distribute work books on mathematics to the students obtaining less than 20 marks, giving one workbook to each of such students. If a work book
costs Rs 5, what sum is required to buy the work books?
(ii) Every student belonging to the highest mark group is entitled to get a prize of Rs. 10. How much amount of money is required for distributing the prize money?
(iii) Every student belonging to the lowest mark—group has to solve 5 problems per day. How many problems, in all, will be solved by the students of this group per day?
(iv) State whether true or false.
a. 17% students have obtained marks ranging from 40 to 49.
b. 59 students have obtained marks ranging from 10 to 29.
(v) What is the number of students getting less than 20 marks?
(vi) What is the number of students getting more than 29 marks?
(vii) What is the number of students getting marks between 9 and 40?
(viii) What is the number of students belonging to the highest mark group?
(ix) What is the number of students obtaining more than 19 marks?
Read the bar graph given in Fig. below and answer the following questions:
(i) What information does it give?
(ii) In which part the expenditure on education is maximum in 1980?
(iii) In which part the expenditure has gone up from 1980 to 1990?
(iv) In which part the gap between 1980 and 1990 is maximum?
Explain the reading and interpretation of bar graphs.
The population of Delhi State in different census years is as given below:
| Census year | 1961 | 1971 | 1981 | 1991 | 2001 |
| Population in Lakhs | 30 | 55 | 70 | 110 | 150 |
The production of oil (in lakh tonnes) in some of the refineries in India during 1982 was given below:
| Refinery: | Barauni | Koyali | Mathura | Mumbai | Florida |
| Production of oil (in lakh tonnes) |
30 | 70 | 40 | 45 | 25 |
Construct a bar graph to represent the above data so that the bars are drawn horizontally.
Draw frequency polygons for each of the following frequency distribution:
(a) using histogram
(b) without using histogram
|
C.I |
5 -15 | 15 -25 | 25 -35 | 35 - 45 | 45-55 | 55-65 |
| ƒ | 8 | 16 | 18 | 14 | 8 | 2 |
Construct a combined histogram and frequency polygon for the following frequency distribution:
| Class-Intervals | 10 - 20 | 20 - 30 | 30 - 40 | 40 - 50 | 50 - 60 |
| Frequency | 3 | 5 | 6 | 4 | 2 |
For the following table, draw a bar-graph
| A | B | C | D | E | F |
| 230 | 400 | 350 | 200 | 380 | 160 |
The frequency distribution has been represented graphically as follows:
| Marks | 0 – 20 | 20 – 40 | 40 – 60 | 60 – 100 |
| Number of Students | 10 | 15 | 20 | 25 |
Do you think this representation is correct? Why?
