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About Graphical Representation — Class 10 ICSE

Plot and interpret histograms, frequency polygons, and cumulative frequency curves. This topic is part of the ICSE Class 10 mathematics syllabus (chapter: Chapter 12). On this page you can practice 60 questions across three difficulty levels — 20 easy, 20 medium, and 20 hard — each with a visual step-by-step solution, plus a timed 10-question mastery test with a live leaderboard. Worked examples and sample questions from the topic are below.

Graphical Representation — solved examples for Class 10 ICSE

Example 1easy

A histogram represents data using:
  1. A)Line segments
  2. B)Rectangular bars with no gaps
  3. C)Circles divided into sectors
  4. D)Scattered points

Step-by-step solution

  1. A histogram uses rectangular bars placed side by side (no gaps) to represent continuous grouped data.
  2. The width represents the class interval and the height represents the frequency.

Answer: Rectangular bars with no gaps

Example 2medium

From the following data, construct a 'less than' cumulative frequency table and find the cumulative frequency just before the median class.

| Class | 0100-10 | 102010-20 | 203020-30 | 304030-40 | 405040-50 |
|---|---|---|---|---|---|
| ff | 77 | 1010 | 1515 | 88 | 1010 |
  1. A)1717
  2. B)1515
  3. C)3232
  4. D)77

Step-by-step solution

  1. cf:
    7,17,32,40,507, 17, 32, 40, 50
  2. n/2 = 25. Median class = 203020-30 (cf = 32 >= 25)
  3. cf before median class:
    =17= 17

Answer: 1717

Example 3hard

The following 'less than' ogive data is given:

| Less than | 1010 | 2020 | 3030 | 4040 | 5050 | 6060 |
|---|---|---|---|---|---|---|
| cf | 66 | 1818 | 3636 | 5858 | 7676 | 8080 |

Estimate the interquartile range (IQR = Q3Q1Q_3 - Q_1).
  1. A)16.516.5
  2. B)18.218.2
  3. C)17.717.7
  4. D)19.419.4

Step-by-step solution

  1. n = 80, n/4 = 20, 3n/4 = 60
  2. Q1Q_1: cf at 20 = 18, cf at 30 = 36. Q1 class: 203020-30
  3. Q1Q_1:
    =20+201818×10=20+1.11=21.11= 20 + \frac{20 - 18}{18} \times 10 = 20 + 1.11 = 21.11
  4. Q3Q_3: cf at 40 = 58, cf at 50 = 76. Q3 class: 405040-50
  5. Q3Q_3:
    =40+605818×10=40+1.11=41.11= 40 + \frac{60 - 58}{18} \times 10 = 40 + 1.11 = 41.11
  6. IQR:
    =41.1121.11=20= 41.11 - 21.11 = 20

Answer: 17.717.7

Practice questions on Graphical Representation

  1. Q1.easy

    In a histogram, the area of each bar is proportional to:
    1. A)The class width
    2. B)The frequency of that class
    3. C)The cumulative frequency
    4. D)The class mark
    Show answer

    Answer: The frequency of that class

    Hint: Area = width × height. For equal class widths, height alone represents frequency.

  2. Q2.easy

    A frequency polygon is drawn by plotting:
    1. A)Frequencies against upper class boundaries
    2. B)Frequencies against class marks (mid-values)
    3. C)Cumulative frequencies against upper boundaries
    4. D)Frequencies against lower class boundaries
    Show answer

    Answer: Frequencies against class marks (mid-values)

    Hint: The frequency polygon connects the midpoints of the tops of histogram bars.

  3. Q3.easy

    The class mark of the interval 203020 - 30 is:
    1. A)2020
    2. B)3030
    3. C)2525
    4. D)5050
    Show answer

    Answer: 2525

    Hint: Class mark = (Lower limit + Upper limit) / 2.

  4. Q4.medium

    A 'less than' ogive passes through the points (10,5)(10, 5), (20,15)(20, 15), (30,30)(30, 30), (40,42)(40, 42), (50,50)(50, 50). What is the frequency of the class 203020-30?
    1. A)1515
    2. B)3030
    3. C)1010
    4. D)1212
    Show answer

    Answer: 1515

    Hint: The frequency of a class = cf at its upper boundary minus cf at its lower boundary.

  5. Q5.medium

    From the following ogive data, estimate the median.

    | Less than | 1010 | 2020 | 3030 | 4040 | 5050 | 6060 |
    |---|---|---|---|---|---|---|
    | cf | 55 | 1313 | 2828 | 4242 | 4848 | 5050 |
    1. A)2828
    2. B)3030
    3. C)25.6725.67
    4. D)27.3327.33
    Show answer

    Answer: 27.3327.33

    Hint: n = 50, n/2 = 25. Median class is where cf first reaches 25. Interpolate.

  6. Q6.medium

    Convert the following inclusive classes to exclusive classes: 110,1120,2130,31401-10, 11-20, 21-30, 31-40. The adjusted first class is:
    1. A)0.510.50.5-10.5
    2. B)1101-10
    3. C)0110-11
    4. D)0.59.50.5-9.5
    Show answer

    Answer: 0.510.50.5-10.5

    Hint: Adjustment factor = (11-10)/2 = 0.5. Subtract from lower, add to upper.

  7. Q7.hard

    A histogram has unequal class widths as shown. Find the adjusted height (frequency density) for the class 205020-50 with frequency 3030.

    Minimum class width in the distribution = 1010.
    1. A)3030
    2. B)1010
    3. C)1515
    4. D)33
    Show answer

    Answer: 1010

    Hint: Frequency density = frequency / class width. Or adjust: height = frequency × (minimum width / class width).

  8. Q8.hard

    The following data gives the distribution of wages. Draw a histogram and estimate the mode graphically.

    | Wages | 800840800-840 | 840880840-880 | 880920880-920 | 920960920-960 | 9601000960-1000 |
    |---|---|---|---|---|---|
    | Workers | 1414 | 2020 | 3030 | 2222 | 1414 |

    The mode estimated from the histogram is approximately:
    1. A)892892
    2. B)896896
    3. C)900900
    4. D)888888
    Show answer

    Answer: 896896

    Hint: Draw diagonals from the top corners of the modal class bar to adjacent bars and find the intersection.

  9. Q9.hard

    From the following data, construct both ogives and find the median graphically.

    | Class | 0100-10 | 102010-20 | 203020-30 | 304030-40 | 405040-50 |
    |---|---|---|---|---|---|
    | ff | 55 | 1515 | 2020 | 1212 | 88 |

    The intersection of the two ogives occurs at approximately which x-value?
    1. A)2222
    2. B)2424
    3. C)2525
    4. D)23.523.5
    Show answer

    Answer: 2525

    Hint: The intersection gives the median. Verify using the median formula.

These are 9 of the 60 questions available for Graphical Representation. Start practicing above to unlock visual solutions, AI coaching, and the topic leaderboard — completely free.