Answer:
range = 6
IQR = 3.5
Explanation:
range is greatest - least
18-12=6
IQR is the difference between quartile 3 and quartile 1
to find IQR you would want to put the numbers in order first
12, 12, 13, 13, 14, 15, 17, 18
then find the median of that set of numbers (you don't need to find the exact number just know where it is)
12, 12, 13, 13, || 14, 15, 17, 18
so the median is between 13 and 14 (where the || is)
then we find the median on both sides of the ||
find the median of 12, 12, 13, 13 and 14, 15, 17, 18
12, 12, || 13, 13 and 14, 15, || 17, 18
the medians are 12.5 and 16
subtract 12.5 from 16 to get 3.5
the IQR is 3.5