A statistical data can be expressed by diagram, chart, etc., in order to make the data grasped immediately. In this chapter, students will be studying only about histograms, frequency polygon and Ogive (cumulative frequency curve). This chapter consists of only one exercise, solutions which can be found at Selina Solutions for Class 10 Mathematics. This is a vital resource for students in order to prepare for their exams. It is prepared by experienced faculty at BYJU’S, keeping in mind the latest ICSE guidelines. Additionally, this resource is available free of cost and can be accessed at any time. Further, the Selina Solutions for Class 10 Mathematics Chapter 23 Graphical Representation (Histograms and Ogives) are available in a PDF, provided in the link below.
Selina Solutions Concise Maths Class 10 Chapter 23 Graphical Representation (Histograms and Ogives) Download PDF
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Access Selina Solutions Concise Maths Class 10 Chapter 23 Graphical Representation (Histograms and Ogives)
Exercise 23 Page No: 348
1. Draw histograms for the following frequency distributions:
(i)
| Class Interval | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 | 50-60 |
| Frequency | 12 | 20 | 26 | 18 | 10 | 6 |
(ii)
| Class Interval | 10-16 | 16-22 | 22-28 | 28-34 | 34-40 |
| Frequency | 15 | 23 | 30 | 20 | 16 |
(iii)
| Class Interval | 30-39 | 40-49 | 50-59 | 60-69 | 70-79 |
| Frequency | 24 | 16 | 09 | 15 | 20 |
(iv)
| Class Marks | 16 | 24 | 32 | 40 | 48 | 56 | 64 |
| Frequency | 8 | 12 | 15 | 18 | 25 | 19 | 10 |
Solution:
(i)
| Class Interval | Frequency |
| 0-10 | 12 |
| 10-20 | 20 |
| 20-30 | 26 |
| 30-40 | 18 |
| 40-50 | 10 |
| 50-60 | 06 |
Steps of construction:
(a) Taking suitable scales, mark the class intervals on x-axis and the frequencies on y-axis.
(b) Construct rectangles with class intervals as bases and corresponding frequencies as heights.
(ii)
| Class Interval | Frequency |
| 10-16 | 15 |
| 16-22 | 23 |
| 22-28 | 30 |
| 28-34 | 20 |
| 34-40 | 16 |
Steps of construction:
(a) Taking suitable scales, mark the class intervals on x-axis and frequency on y-axis.
(b) Construct rectangles with class intervals as bases and corresponding frequencies as heights.
(iii)
| Class Interval
(Inclusive form) |
Class Interval
(Exclusive Form) |
Frequency |
| 30-39 | 29.5-39.5 | 24 |
| 40-49 | 39.5-49.5 | 16 |
| 50-59 | 49.5-59.5 | 09 |
| 60-69 | 59.5-69.5 | 15 |
| 70-79 | 69.5-79.5 | 20 |
Steps of construction:
(a) Convert the data into exclusive form. [Here, adjustment factor = 0.5]
(b) Taking suitable scales, mark the class intervals on x-axis and the frequency on y-axis.
(c) Construct rectangles with class intervals as bases and corresponding frequencies as heights.
(iv)
From the given data:
| Class Marks | Class Intervals | Frequency |
| 16 | 12-20 | 08 |
| 24 | 20-28 | 12 |
| 32 | 28-36 | 15 |
| 40 | 36-44 | 18 |
| 48 | 44-52 | 25 |
| 56 | 52-60 | 19 |
| 64 | 60-68 | 10 |
Steps of construction:
(a) Convert the class marks into class intervals.
(b) Taking suitable scales, mark class intervals on x-axis and frequency on y-axis.
(c) Construct rectangles with class intervals as bases and corresponding frequencies as heights.
2. Draw cumulative frequency curve (ogive) for each of the following distributions:
(i)
| Class
Interval |
10-15 | 15-20 | 20-25 | 25-30 | 30-45 | 35-40 |
| Frequency | 10 | 15 | 17 | 12 | 10 | 08 |
(ii)
| Class Interval | 10-19 | 20-29 | 30-39 | 40-49 | 50-59 |
| Frequency | 23 | 16 | 15 | 20 | 12 |
Solution:
(i)
| Class Interval | Frequency |
| 10-15 | 10 |
| 15-20 | 15 |
| 20-25 | 17 |
| 25-30 | 12 |
| 30-35 | 10 |
| 35-40 | 08 |
Steps of construction:
(a) Taking suitable scales, mark the class intervals on x-axis and the frequencies on y-axis.
(b) Construct rectangles with class intervals as bases and corresponding frequencies as heights.
(c) Join the mid-points of the rectangle to obtain the ogive.
(ii)
| Class Interval
(Inclusive) |
Class Interval
(Exclusive) |
Frequency | Cumulative
Frequency |
| 10-19 | 9.5-19.5 | 23 | 23 |
| 20-29 | 19.5-29.5 | 16 | 39 |
| 30-39 | 29.5-39.5 | 15 | 54 |
| 40-49 | 39.5-49.5 | 20 | 74 |
| 50-59 | 49.5-59.5 | 12 | 86 |
| Total | 86 |
Steps of construction:
(a) Convert the data into exclusive form. [Here, adjustment factor = 0.5]
(b) Taking suitable scales, mark the class intervals on x-axis and the frequencies on y-axis.
(c) Construct rectangles with class intervals as bases and corresponding frequencies as heights.
(d) Join the mid-points of the rectangle to obtain the ogive.
3. Draw an ogive for each of the following distributions:
(i)
| Marks Obtained | less
than 10 |
less
than 20 |
less
than30 |
less
than 40 |
less
than 50 |
| No. of
Students |
8 | 25 | 38 | 50 | 67 |
(ii)
| Age in years (less than) | 10 | 20 | 30 | 40 | 50 | 60 | 70 |
| Cumulative Frequency | 0 | 17 | 32 | 37 | 53 | 58 | 65 |
Solution:
(i)
| Marks Obtained | No. of students (c.f.) |
| less than 10 | 8 |
| less than 20 | 25 |
| less than 30 | 38 |
| less than 40 | 50 |
| less than 50 | 67 |
Steps Of construction:
(a) Plot the points (10, 8), (20, 25), (30, 38), (40, 50) and (50, 67) on the graph.
(b) Join them with free hand to obtain an ogive.
(ii)
| Age in years
(less than) |
Cumulative
Frequency |
| 10 | 0 |
| 20 | 17 |
| 30 | 32 |
| 40 | 37 |
| 50 | 53 |
| 60 | 58 |
| 70 | 65 |
Steps Of construction:
(a) Plot the points (10, 0), (20, 17), (30, 32), (40, 37), (50, 53), (60, 58) and (70, 65) on the graph.
(b) Join them with free hand to obtain an ogive.
4. Construct a frequency distribution table for the number given below, using the class intervals 21-30, 31-40 … etc.
75, 67, 57, 50, 26, 33, 44, 58, 67, 75, 78, 43, 41, 31, 21, 32, 40, 62, 54, 69, 48, 47, 51, 38, 39, 43, 61, 63, 68, 53, 56, 49, 59, 37, 40, 68, 23, 28, 36, 47
Use the table obtained to draw:
(i) a histogram (ii) an ogive
Solution:
(i)
(ii)
Plot the points (30,4), (40,13), (50,22), (60,29), (70,37) and (80,40) on the graph and join them with free hand to obtain an ogive.
The given solutions are as per the 2019-20 Concise Selina textbook. The Selina Solutions for the academic year 2020-21 will be updated soon.
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