The Range Example


A testing lab wishes to test two experimental brands of outdoor paint to see how long each will last before fading. The testing lab makes 6 gallons of each paint to test. Since different chemical agents are added to each group and only six cans are involved, these two groups constitute two small populations. the results (in months) are shown

Brand A Brand B
10 35
60 45
50 30
30 35
40 40
20 25

We will now find the range of both the data set for brand A and brand B and compare.


Step 1: Find the largest value

The largest value for

Brand A: 60

Brand B: 45


Step 2: Find the smallest value

The smallest value for

Brand A: 10 

Brand B: 25


Step 3: Subtract the smallest value from the largest value, that is Range= Largest - Smallest

Brand A Range: 60-10=50

Brand B Range: 45-25=20


We see that Brand A has the larger value possible... yet also has a very large range, this means that the results are less consistent.