Statistical Diagrams

விளையாடிக் கற்றுக்கொள்ளுங்கள்

ஆற்றல் சம்பாதிக்க இந்த கேள்விகளுக்குப் பதிலளியுங்கள், பின்னர் மீன் பிடித்து ஆராயுங்கள். கணக்கு தேவையில்லை.

ஆசிரியர்களுக்கு: Statistical Diagrams (Maths [CIE], Core)-க்கான தயாரான பாட ஸ்லைடுகள், திருப்புதல் குறிப்புகள், வரைபடங்கள் — உங்கள் பாடத்தில் அவற்றைப் பயன்படுத்தவும், அல்லது மாணவர்கள் நேரலை விளையாட்டாக விளையாடும் ஊடாடும் வகுப்பு செயல்பாடாக தலைப்பை இயக்கவும்.

பாட குறிப்புகள்

Stem & Leaf Diagrams

A stem-and-leaf diagram displays an ordered list of data using digits; two-digit numbers split into tens (stem) and units (leaf).
The stem is written vertically, leaves horizontally in order; include a key showing how values are formed (e.g., 1|8 means 18).
To find the median, cross out numbers from both ends until the middle is reached; remember to include the stem (e.g., median = 26, not 6).
The range is the difference between the highest and lowest values; the highest is at the end of the last stem.

Tally Charts & Frequency Tables

A tally chart uses vertical lines to count data; the fifth line is drawn diagonally across the previous four (e.g., ||||).
Convert tally marks to a frequency table by counting totals (e.g., |||| || = 5+2 = 7).
Frequency tables show how many times each item appears; they can be used to find the mode (most frequent item).

Bar Charts & Pictograms

A bar chart displays discrete data with bars of equal width separated by gaps; the vertical axis shows frequency, horizontal axis shows categories.
The mode is the category with the highest bar; for grouped data, the median can be found by converting to a table and using cumulative frequency.
A pictogram uses symbols to represent frequency; a key shows the value of one symbol (e.g., one shoe = 2 students).
Half or quarter symbols can represent fractions of the key value; pictograms have no axes.

Bar chart: shoe sizes in class 11A

Pie Charts

A pie chart is a circle divided into sectors showing relative proportions; each sector angle is (frequency/total) × 360°.
To draw, calculate each sector angle, draw a vertical radius, then use a protractor to mark angles in order.
If a pie chart says 'not to scale', use ratio and proportion (e.g., 30° = 15 people → 1° = 0.5 people).
The total angle is 360°, representing the total frequency; angles are proportional to frequencies.

Pie chart: favourite colours (30 students)

Reading & Interpreting Statistical Diagrams

Read titles, axis labels, and keys carefully; note units (e.g., thousands) and any extreme values (outliers).
Describe trends using numbers from the graph (e.g., 'temperature decreased from 12°C to 9°C over 3 days').
Be cautious about drawing conclusions: data may be unrepresentative (e.g., only one week) or biased.
Use mode, median, mean, or range to support explanations; write in full sentences copying exact wording.

Garden temperature at 7am each day

Comparing Statistical Diagrams

Compare trends (increases, decreases, peaks) and spread using range; use numbers from both data sets.
Calculate averages (mean, median, mode) to compare central tendency; relate calculations to context.
Comment on similarities and differences; note any outliers or unusual patterns.
State limitations: data may be from a specific period (e.g., opening week) and not representative of normal patterns.

Comparing books bought by male and female customers

ஸ்லைடுகள்

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பதிவு செய்க — இலவசம்உள்நுழைக

பயிற்சி கேள்விகள்

இலவச முன்னோட்டம் — 52-இல் 8 கேள்விகள். அனைத்தையும் பார்க்க பதிவு செய்யவும்.

1.In a stem-and-leaf diagram, what does the key '3|5' mean?
Easy
- A35
- B3.5
- C53
- D305
2.What is the mode of the data set: 2, 3, 3, 5, 7, 7, 7, 8?
Easy
- A3
- B5
- C7
- D8
3.A pictogram uses one symbol to represent 4 cars. How many symbols are needed to show 20 cars?
Easy
- A4
- B5
- C16
- D80
4.In a bar chart, the height of a bar shows the
Easy
- Afrequency
- Bcategory
- Ctotal
- Drange
5.What is the total angle in a pie chart?
Easy
- A180°
- B270°
- C360°
- D90°
6.A pie chart has a sector of 90° representing 30 people. How many people does the whole pie chart represent?
Medium
- A90
- B120
- C30
- D360
7.In a frequency table, the tally marks '|||| |||' represent what frequency?
Easy
- A7
- B8
- C9
- D5
8.The number of cars in a car park each day: 124, 130, 129, 116, 132, 120, 127, 107, 118, 114. What is the range?
Easy
- A25
- B23
- C24
- D26

மேலும் கேள்விகள்

9.A dual bar chart compares the number of pets owned by Year 7 and Year 8 students. The bar for '1 pet' in Year 7 reaches 10, and in Year 8 reaches 8. What is the difference in the number of students who own exactly 1 pet between Year 7 and Year 8? | Pets owned | Year 7 | Year 8 | |---|---|---| | 1 pet | 10 | 8 |
Easy
- A2
- B18
- C10
- D8
10.In a pie chart showing favourite colours, the sector for Blue is 108°. If 15 students chose Blue, how many students are there in total?
Medium
- A50
- B45
- C60
- D30
11.The stem-and-leaf diagram shows test scores: Stem: 4 | 5 8, 5 | 1 3 6 9, 6 | 0 2 4 7 7, 7 | 1 3. Key: 4|5 means 45. What percentage of students scored 70 or more?
Medium
- A20%
- B25%
- C15%
- D30%
12.In a tally chart, what does the symbol '卌' represent?
Easy
- A5
- B4
- C10
- D1
13.What is the mode of the colours: red, blue, red, green, blue, red, yellow?
Easy
- Ared
- Bblue
- Cgreen
- Dyellow
14.A bar chart shows the number of books read by students. The bar for '3 books' has height 8. How many students read exactly 3 books? | Books read | Frequency | |---|---| | 3 | 8 |
Easy
- A3
- B8
- C11
- D5
15.A pictogram shows the number of pizzas sold. One symbol represents 5 pizzas. If there are 3 and a half symbols, how many pizzas were sold?
Easy
- A15
- B17.5
- C18
- D20
16.In a stem-and-leaf diagram, what does the key '4|7' represent?
Easy
- A4.7
- B47
- C74
- D4/7
17.A tally chart shows the following: Red: |||| ||, Blue: ||||, Green: |||. What is the frequency of Red?
Easy
- A5
- B6
- C7
- D8
18.In a bar chart showing favourite colours, the bar for 'Blue' has height 8. How many people chose Blue? | Favourite colour | Frequency | |---|---| | Blue | 8 |
Easy
- A4
- B8
- C16
- D80
19.A pictogram uses one symbol to represent 5 cars. How many symbols are needed to show 35 cars?
Easy
- A5
- B6
- C7
- D8
20.A pie chart has a sector of 45° representing 10 people. How many people does the whole pie chart represent?
Medium
- A40
- B80
- C120
- D160
21.The stem-and-leaf diagram shows ages: Stem: 1 | 2 5 8, 2 | 0 3 4 7, 3 | 1 6, Key: 1|2 = 12. What is the median age?
Medium
- A23
- B24
- C25
- D27
22.A bar chart shows the number of books read: 0 books: 3 students, 1 book: 5, 2 books: 8, 3 books: 4. What is the total number of students? | Books read | 0 | 1 | 2 | 3 | |---|---|---|---| | Students | 3 | 5 | 8 | 4 |
Easy
- A18
- B19
- C20
- D21
23.A pie chart shows favourite sports: Football 90°, Rugby 120°, Tennis 60°, Cricket 90°. What fraction chose Rugby?
Medium
- A1/3
- B1/4
- C1/2
- D2/3
24.In a tally chart, what does '|||| |||' represent?
Easy
- A7
- B8
- C9
- D10
25.A dual bar chart compares pets: Year 7 bar for 'Cat' reaches 12, Year 8 bar reaches 9. How many more Year 7 students have a cat? | Pet | Year 7 | Year 8 | |---|---|---| | Cat | 12 | 9 |
Easy
- A2
- B3
- C4
- D21
26.A pie chart is drawn for 120 students. The sector for 'Maths' is 60°. How many students chose Maths?
Easy
- A10
- B20
- C30
- D40
27.The stem-and-leaf diagram shows test scores: Stem: 5 | 2 4, 6 | 1 3 5, 7 | 0 2 8, 8 | 1 3, Key: 5|2 = 52. What percentage of students scored 70 or more?
Medium
- A40%
- B50%
- C60%
- D70%
28.A frequency table shows: Number of goals: 0 (5), 1 (8), 2 (6), 3 (1). What is the mean number of goals?
Medium
- A1.0
- B1.1
- C1.2
- D1.3
29.A bar chart shows rainfall (mm): Jan 80, Feb 60, Mar 70, Apr 50, May 40, Jun 30. What is the range? | Month | Jan | Feb | Mar | Apr | May | Jun | |---|---|---|---|---|---|---| | Rainfall (mm) | 80 | 60 | 70 | 50 | 40 | 30 |
Easy
- A30 mm
- B40 mm
- C50 mm
- D80 mm
30.A pictogram shows pizzas sold: Monday: 3 symbols, Tuesday: 2.5 symbols, Wednesday: 4 symbols. If one symbol = 4 pizzas, how many pizzas were sold on Tuesday? | Day | Symbols | |---|---| | Monday | 3 | | Tuesday | 2.5 | | Wednesday | 4 |
Easy
- A8
- B10
- C12
- D14
31.A pie chart shows 360 students. The sector for 'Bus' is 72°. How many students travel by bus?
Easy
- A60
- B72
- C90
- D120
32.A pie chart shows the favourite sports of 120 students. The sector for football has an angle of 90°. How many students chose football?
Easy
- A30
- B45
- C60
- D90
33.The stem-and-leaf diagram shows the ages of 14 people. Stem: 1 | 2 5 8, 2 | 0 3 4 7 9, 3 | 1 2 6 8, 4 | 0 1. Key: 1|2 = 12 years. What is the median age?
Medium
- A27
- B28
- C29
- D30
34.A tally chart shows: Red: |||| |||, Blue: |||| ||, Green: ||||. What is the frequency of Red?
Easy
- A7
- B8
- C9
- D10
35.A pie chart shows favourite colours: Blue 108°, Red 72°, Green 90°, Yellow 90°. If 15 students chose Blue, how many students are there in total?
Medium
- A50
- B45
- C60
- D30
36.A pie chart has a sector of 90° representing 15 people. How many people does the whole pie chart represent?
Medium
- A60
- B360
- C30
- D45
37.In a stem-and-leaf diagram, the stem represents which digit(s) of a two-digit number?
Easy
- AThe tens digit
- BThe units digit
- CBoth digits
- DThe hundreds digit
38.In a bar chart, the bars should touch each other.
Easy
True or false?
39.Which of the following are true about a pie chart? (Select all that apply)
Medium
- AIt shows the relative proportions of categories.
- BThe total angle is 360°.
- CIt is best for showing exact frequencies.
- DEach sector's angle is proportional to the frequency.
40.Match each type of diagram with its primary use.
Medium
- Bar chart
- Pie chart
- Stem-and-leaf diagram
- Compare frequencies of categories
- Show proportions of a whole
- Display ordered list of data
41.Put the following steps for drawing a pie chart in the correct order.
Medium
- Calculate the angle for each category.
- Draw a circle and a radius to the top.
- Use a protractor to mark each sector.
- Label each sector.
42.Which of the following are true about a stem-and-leaf diagram? (Select all that apply)
Medium
- AIt shows the data in order
- BIt is useful for finding the mode
- CIt can display data with more than two digits
- DThe key explains how to read the digits
43.A pie chart shows the favourite colours of 60 students. The sector for Blue has an angle of 72°. How many students chose Blue?
Easy
- A12
- B15
- C20
- D24
44.A tally chart shows Red: |||| |||, Blue: ||||, Green: |||. What is the frequency of Red?
Easy
- A5
- B7
- C8
- D10
45.What is the mode of the following data set? 3, 5, 5, 7, 9, 9, 9, 10
Easy
46.Complete the sentence.
Easy
In a tally chart, the symbol that represents a count of five is ____.
47.In a stem-and-leaf diagram, the key is 4|7 = 47. What value is represented by 6|2?
Easy
48.A pie chart has a sector of 60° representing 10 people. How many people does the whole pie chart represent?
Medium
49.What is the mode of the following data set? 4, 7, 7, 9, 10, 10, 10, 12
Easy
50.Explain why a stem-and-leaf diagram is useful for finding the median.
Medium
51.In a stem-and-leaf diagram, the key is 4|7 = 47. What value is represented by 6|2?
Easy
- A74
- B62
- C68
- D56
52.A pie chart has a sector of 60° representing 10 people. How many people does the whole pie chart represent?
Medium
- A60 people
- B54 people
- C66 people
- D72 people

திருப்புதல் குறிப்புகள்

## Statistical Diagrams - Quick Revision ### Stem & Leaf Diagrams - Split two-digit numbers into stem (tens) and leaf (units). - Write stems vertically, leaves horizontally in order. - **Key**: e.g., 1|8 means 18. - **Median**: middle value; cross out from ends until one or two remain; if two, find midpoint. ### Tally Charts & Frequency Tables - Tally: count in groups of five (||||). - Frequency table: total tallies for each category. ### Bar Charts & Pictograms - **Bar chart**: discrete data; bars separated, equal width; mode = highest bar. - **Pictogram**: uses symbols; key shows value per symbol; half/quarter symbols allowed. ### Pie Charts - Sector angle = (frequency / total) × 360°. - Total angle = 360°. - Use ratio: if angle a° represents value v, then 1° = v/a, total = (360 × v)/a. ### Reading & Interpreting Diagrams - Read titles, axes, keys, units. - Look for trends (increase, decrease, peak). - Use numbers from graph; write full sentences. - Consider if data is representative (e.g., small sample, biased). ### Comparing Diagrams - Compare averages (mean, median, mode) and spread (range). - Use numbers and context. - Comment on similarities/differences, outliers. ### Key Formulas - **Range** = highest value – lowest value. - **Mean** = sum of values / number of values. - **Median**: middle value when ordered. - **Mode**: most frequent value. - **Probability** = number of favourable outcomes / total outcomes.

Stem-and-leaf diagram: A simple way to display ordered data using digits; the stem is the tens digit and the leaf is the units digit.
Tally chart: A quick way to count data using groups of five vertical lines.
Frequency table: A table showing how many times each item appears.
Bar chart: A visual representation of discrete data using bars of equal width separated by gaps.
Pictogram: A diagram using symbols to represent data; a key shows the value of one symbol.
Pie chart: A circle divided into sectors representing categories; sector angle is proportional to frequency.
Mode: The most frequently occurring value.
Median: The middle value when data is ordered.
Range: The difference between the highest and lowest values.
Mean: The sum of all values divided by the number of values.

ஃப்ளாஷ் கார்டுகள்

What is a stem-and-leaf diagram?

A stem-and-leaf diagram is a simple way to display an ordered list of data using digits. Two-digit numbers are split into a tens digit (the stem) and a units digit (the leaf).

In a stem-and-leaf diagram, how is the number 25 represented?

25 is represented as 2 | 5, where 2 is the stem (tens) and 5 is the leaf (units).

What is the purpose of the key in a stem-and-leaf diagram?

The key shows how values are formed from digits and should include units. For example, '2 | 5 represents 25 years old'.

How do you find the median from a stem-and-leaf diagram?

The median is the middle number. Since data values are already in order, cross out numbers from the beginning and end until they meet in the middle. If two numbers remain, find the midpoint between them.

What is a tally chart?

A tally chart is a quick way to count data. Each time you count an item, draw a vertical line. For the fifth count, draw a diagonal line through the four vertical lines (||||). Continue counting in sets of five.

What is a frequency table?

A frequency table counts how many times an item appears. Tally charts can be converted into frequency tables by finding the totals.

What is a bar chart?

A bar chart is a visual way to represent discrete data. The horizontal axis shows outcomes, the vertical axis shows frequency. Bars should be separated by gaps and have equal widths.

What is a pictogram?

A pictogram is an alternative to a bar chart where frequency is represented by symbols. A key shows the value of one symbol. Half and quarter symbols are often used.

In a pictogram, if one symbol represents 2 students, how many students does half a symbol represent?

Half a symbol represents 1 student.

What is a pie chart?

A pie chart is a circle divided into sectors that represent different categories. The sectors show the relative proportions of the categories, not the actual frequencies.

How do you calculate the sector angle for a category in a pie chart?

Multiply the fraction of the total frequency for that category by 360°. For example, if 11 out of 30 students chose red, the angle is (11/30) × 360° = 132°.

In a pie chart, what does 360° represent?

360° represents the total frequency.

If a sector of 30° represents 15 people, what does 1° represent?

1° represents 0.5 people (15 ÷ 30 = 0.5).

How do you find the mode from a bar chart?

The mode is the outcome with the highest bar (the tallest bar).

How do you find the total frequency from a bar chart?

Add up the heights (frequencies) of all the bars.

When comparing two data sets using statistical diagrams, what measures should you compare?

Compare averages (mean, median, mode) and the range (spread) of the data sets.

What does the range tell you about a data set?

The range tells you the spread of the data; it is the difference between the highest and lowest values.

What is an outlier in a statistical diagram?

An outlier is an extreme value that is much higher or lower than the rest of the data.

Why might a pie chart be labelled 'not to scale'?

It means you should use ratio and proportion methods to answer questions, not measure angles with a protractor.

What is a dual bar chart?

A dual bar chart has bars in pairs (side-by-side) for each outcome, used to compare two data sets.

How do you find the median from a bar chart?

Convert the bar chart data into a table, then use the method for finding the median from a frequency table.

What should you look for when interpreting a statistical diagram?

Read titles, axes labels, keys, and units. Look for trends, outliers, and use numbers from the graph to support conclusions.

Give one reason why data from a graph might not be representative.

The data set may be too small, biased, or only cover a specific time period (e.g., opening week) that is not typical.

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இந்த தலைப்பிற்கான ஒவ்வொரு கேள்வியையும், ஸ்லைடுகளையும், ஃப்ளாஷ் கார்டுகளையும் மற்றும் திருப்புதல் குறிப்புகளையும் பார்க்க இலவச கணக்கை உருவாக்கவும்.

பதிவு செய்க — இலவசம்உள்நுழைக

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