Download Stem-and-Leaf Diagrams and Box Plots Exercises - Prof. Akerman and more Slides Mathematics in PDF only on Docsity!
- The ages, in years, of 11 students are shown.
a) Work out the median age of the students.
b) Work out the range of the ages.
c) Write down the mode of the ages.
d) What fraction of the students are less than 16 years
old?
- If there are 99 numbers in order from smallest to
largest, what is the position of the median?
- If a population increased 50% in one year, then
decreased by 50% for two years in a row, what is the
change over the 3 years?
If we start with 100, over the years the population is
100, 150, 75, 32.5. Decrease by 67.5%
Stem and leaf diagrams, box plots 10 June 2025
5 min
8
8
8
8
6 means 56 metres
Key
31 metres
78 metres
Stem Leaf
Data:
31, 32, 34, 42, 45, 47, 48, 55, 55, 56, 59, 60, 61,
71, 73, 78
8
8
8
8
8
8
8
8
6 means 156 kg
Key
Work out the range of
the masses.
The stem-and-leaf diagram shows the
masses of 19 animals.
Have a think
What is the median mass?
8
8
8
8
The data shows information about the ages of some people
in years.
Dani draws a stem-and-leaf diagram for the data.
What mistakes has she made?
She has not drawn an ordered
stem-and-leaf diagram.
She hasn’t drawn a key.
She has missed the number 73 out.
Have a think
The back-to-back stem-and-leaf diagram shows the test
scores of boys and girls in a group.
8
8
8
8
8
8
8
8
boys girls
5 means
25 marks for girls
26 marks for boys
Key
There are 17 boys in total.
There are 15 girls in total.
What is the highest score?
49 marks.
Have a think
The back-to-back stem-and-leaf diagram shows the test
scores of boys and girls in a group.
8
8
8
8
8
8
8
8
boys girls
5 means
26 marks for boys
25 marks for girls
Key
Work out the range of the
boys’ scores.
Have a think
The back-to-back stem-and-leaf diagram shows the test
scores of boys and girls in a group.
8
8
8
8
8
8
8
8
boys girls
5 means
26 marks for boys
25 marks for girls
Key
Work out the median score
for the girls.
The median score for the
girls is 28 marks.
Have a think
The back-to-back stem-and-leaf diagram shows the test
scores of boys and girls in a group.
8
8
8
8
8
8
8
8
boys girls
5 means
26 marks for boys
25 marks for girls
Key
Work out the median score
for the boys.
The median score for the
boys is 29 marks.
Have a go at the
worksheet on stem and
leaf diagrams
Start with q1, 3, 6, 7
Smallest
Value
Lower
Quartile
Median
Upper
Quartile
Greatest
Value
Each bracket represents 25% of the data
Box plots
Have a think
0 10 20 30 40 50 60
The box plot shows the test scores for some students.
Decide whether each statement is true or false.
50% of the students got 30 marks or more.
The distribution shows that a higher number of
students scored closer to 60 marks than 0 marks.
False. The median is 42 marks so 50% of the students
got 42 marks or more on the test.
True. The box plot is not symmetrical, it is skewed to
the right, so a higher number of students are closer to
60 marks than 0 marks.
Test score
Have a think
Find the
Median
Lower quartile
Upper quartile
Here are the heights of 12 students to the nearest
tenth of a metre.
0
40
60
80
20
10 20 30 40 50 60
Age (years)
Cumulative frequency
0
10 20 30 40 50 60
Age (years)
Use the cumulative
frequency diagram to
construct a box plot.
Have a think
What percentage
of the items cost
more than £40?
0
10 20 30 40 50 60
Cost (£)
UQ
The box plot shows the cost , (£), of 200 items in a shop.
How many items cost
less than £
LQ
25% of 200
50 items cost less than £
Have a think
