Definition: A Range is the difference between the highest value and lowest value among the given set observations.
Formula:
Range = Highest Value  Lowest Value
Go through the following example to further understanding:
Example 1  Heights of girls (in cm) in a class are as
146, 121, 127, 149, 131, 135, 125, 141, 151, 137
Find the range of girl's height ?
Answer 
Highest height of girl = 151 cm
Lowest height of girl = 121 cm
Range = Highest height  Lowest height
Range = 151  121
Range = 30 cm
Example 2  Following are the numbers obtained by students in Maths subject:
85, 77, 60, 91, 72, 83, 66, 97, 83, 79
What is the range of the data ?
Answer 
Highest marks obtained = 97
Lowest marks obtained = 60
Range = Highest Marks  Lowest Marks
Range = 97  60
Range = 37
