Summarising data
Find the outlier: 3 6 9 12 15 18 40
Outlier = 40
The average of a data set
Mean
True or false? The mean and median of a box plot are always the same
False
The difference between the upper quartile (Q3) and the lower quartile (Q1)
Interquartile range (IQR)
First five multiples of 10
10 20 30 40 50
Find the median: 1 2 3 4 5 6
Even number of values
(Middle value 1 + middle value 2) / 2
= (3 + 4) / 2
= 3.5
The middle value of a data set
Median
What are the 5 elements of a box plot checklist?
Minimum value
Q1
Q2 (median)
Q3
Maximum value
Find the range: 19 23 56 62 67 68 73 76 79 81 85 89 96
Maximum value - minimum value
= 96 - 19
= 77
Factors of 25
1, 5, 25
Find the mode: 6 9 10 46 57 22 63 9 8 2
Most common = 9
The most common value in a data set
Mode
Which three elements form the 'box' in a box plot?
Q1
Q2 (median)
Q3
Find the range: 4 7 1 9 42 36 15
Maximum value - minimum value
= 42 - 1
= 41
First five multiples of 7
7, 14, 21, 28, 35
Find the mode: 1 9 7 3 19 66 37 28 1 3 8 21
Most common = 1 and 3
The difference between the lowest and highest values in a data set
Range
What do the whiskers connect in a box plot?
1st whisker = minimum value to Q1
2nd whisker = Q3 to maximum value
Find the IQR: 2 4 6 8 10 12 14 16 18 20
Q1 = 6 and Q3 = 16
Q3 - Q1
= 16 - 6
= 10
Factors of 32
1, 2, 4, 8, 16, 32
Find the median: 13 17 17 20 24 27 27 28
Even number of values
(Middle value 1 + middle value 2) / 2
= (20 + 24) / 2
= 22
A score that is much larger or smaller than the rest of the data
Outlier
Which values would form the 5 elements of a box plot? 1 1 4 8 9 9 9 9 11 16 20
Minimum value = 1
Q1 = 4
Q2 (median) = 9
Q3 = 11
Maximum value = 20
Find the IQR: 1 3 5 6 7 7 8 8 8 23 76 80
Q1 = 5 and Q3 = 23
Q3 - Q1
= 23 - 5
= 18
Equation of a straight line
y = mx + c