Statistics – Basic 6 Mathematics Lesson Note (Third Term)

Data Representation

Data can be shown in different ways to make it easier to understand.

Pictogram

Uses pictures or symbols to show data. Each symbol represents a certain number.

Bar Chart

Uses bars of different heights to show data. The height shows the quantity.

Pie Chart

Uses a circle divided into sections to show parts of a whole.

Measures of Central Tendency

Mode

The number that appears most often in a set of data. 

Example: In 2, 3, 5, 3, 7, 3, 9 – the mode is 3

Median

The middle number when data is arranged in order. 

Example: In 2, 4, 6, 8, 10 – the median is 6

Mean (Average)

Add all numbers and divide by how many numbers there are. 

Example: Mean of 4, 6, 8 = (4+6+8) ÷ 3 = 18 ÷ 3 = 6

Range

The difference between the highest and lowest values. 

Example: In 3, 7, 2, 9, 5 – Range = 9 – 2 = 7

Probability

Probability tells us how likely something is to happen.

• Certain = will definitely happen
• Likely = probably will happen
• Unlikely = probably won’t happen
• Impossible = will never happen

EXERCISES

1. Find the mode:

1. 5, 8, 3, 5, 9, 5, 2. Mode = _______
2. 12, 15, 12, 18, 12, 20. Mode = _______
3. Red, Blue, Red, Green, Red, Yellow. Mode = _______

1. Find the median:

1. 3, 7, 5, 9, 1. Median = _______
2. 10, 14, 12, 16, 18, 8. Median = _______
3. 25, 30, 20, 35, 15. Median = _______

1. Find the mean:

1. 6, 8, 10, 12. Mean = _______
2. 15, 20, 25, 30, 35. Mean = _______
3. 4, 7, 5, 8, 6. Mean = _______

1. Find the range:

1. 12, 8, 15, 3, 11. Range = _______
2. 25, 18, 30, 22, 35. Range = _______
3. 45, 38, 52, 41, 49. Range = _______

1. Data Interpretation: The table shows favorite subjects of 30 students:

1. Which subject is most popular? _______
2. How many more students like Maths than Science? _______
3. What fraction of students like English? _______

1. Probability: A bag contains 5 red balls, 3 blue balls, and 2 green balls.

1. What color ball are you most likely to pick? _______
2. What color ball are you least likely to pick? _______
3. Is it likely or unlikely to pick a blue ball? _______

1. Real Life Problems:

1. Adunni scored these marks in 5 tests: 85, 90, 78, 90, 82.
   1. Mode = _______
   2. Median = _______
   3. Mean = _______
2. The heights of 7 students (in cm) are: 140, 135, 142, 138, 135, 145, 140
   1. Mode = _______
   2. Range = _______
3. In a class survey, 15 students like football, 10 like basketball, 8 like tennis, 7 like swimming. Draw a simple bar chart.

1. Pictogram Reading: 🍎🍎🍎 = 6 apples sold 🍌🍌 = 4 bananas sold
   🥭🥭🥭🥭 = 8 mangoes sold

1. How many fruits were sold in total? _______
2. Which fruit sold the most? _______
3. How many more mangoes than bananas were sold? _______

Answers: 

A: 1.5 2.12 3.Red 

B: 1.5 2.13 3.25 

C: 1.9 2.25 3.6 

D: 1.12 2.17 3.14 

E: 1.Maths 2.6 3.8/30 or 4/15 

F: 1.Red 2.Green 3.Unlikely 

G: 1.Mode=90, Median=85, Mean=85 2.Mode=135&140, Range=10 H: 1.18 2.Mangoes 3.4