1. Histograms are used to show continuous data with equal intervals.

2. Example
The histogram shows the length of time it took a number of children to complete a maths puzzle.
How many children completed this maths puzzle?
What fraction of children complete the puzzle in less than 10 minutes?
What percentage of children took at least 20 minutes to complete the puzzle?

3. Exercise 1
Complete the Tower of Hanoi as quick as you can and keep track time taken.
Draw a histogram to represent the data.
Answer the following questions based on your graph:
(i) Write down the modal time.
(ii) Where does the median lie?
(iii) What percentage of people took less than 1.5 minutes.
Time Taken
0-30s
30-60s
60-90s
90-120s s s
Tally
Frequency

4. The Shape of a Distribution
Symmetrical Distribution (normal distribution):
Real Life Examples: Heights of a random sample of people IQ of a population

5. The Shape of a Distribution
Positive Skew (skewed right):
Real Life Examples: Number of children in a family Age when people get married

6. The Shape of a Distribution
Negative Skew (Skewed Left):
Real Life Examples: Heights of players playing in an NBA game
Ages which people have to get reading glasses