1. Starter Find the medians of these sets of data: 1, 6, 5, 3, 8, 5, 4
11, 15, 17, 12, 19
99, 95, 96, 95, 95
72, 78, 54, 54, 64, 66
= 5
= 15
= 95
= 65

2. 0 < t ≤ 5 5 < t ≤ 10 10 < t ≤ 15 15 < t ≤ 20
The table below shows the number of minutes students were late for their fun Maths lesson in the Autumn Term.
(a) Draw a Cumulative Frequency Diagram of the data
(b) Use it to find the Median, Lower Quartile, Upper Quartile, and Inter Quartile Range
(c) Draw a Box-Plot assuming a minimum time of 0 minutes and a maximum of 25 minutes
Time t (mins)
Number of Students
Cumulative Frequency
0 < t ≤ 5 10
5 < t ≤ 10 16
10 < t ≤ 15 30
15 < t ≤ 20 22
20 < t ≤ 25 2 10 26 56 78 80

3. 80 x x
Cum freq 60 x 40 x 20 x 5 10 15 20 25
t mins

4. x 80 x
Cum freq 60 x
Median = Middle Value 40
QUARTILES
Lower Quartile = ¼ way
Upper Quartile = ¾ way x 20
Interquartile Range
= 15½ - 8½ = 7 mins x 8½
12½
15½ 5 10 15 20 25
t mins

5. Inter quartile range = 15 ½ - 8 ½ = 7 mins
The table below shows the number of minutes students were late for their fun Maths lesson in the Autumn Term.
(a) Draw a Cumulative Frequency Diagram of the data
(b) Use it to find the Median, Lower Quartile, Upper Quartile, and Inter Quartile Range
(c) Draw a Box-Plot assuming a minimum time of 0 minutes and a maximum of 25 minutes
Median = 12 ½ mins
Lower quartile = 8 ½ mins
Upper quartile = 15 ½ mins
Inter quartile range = 15 ½ - 8 ½ = 7 mins

6. 12 ½ 25 8 ½ 15 ½ Minimum value Median Maximum value Lower Quartile
12 ½ 25
Minimum value
8 ½
Median
15 ½
Maximum value
Lower Quartile
Upper Quartile 5 10 15 20 25
t mins

7. What are the differences?
Spring term
Autumn term
What are the similarities?