Answer:
Option c. Range = 7 IQR = 4.5
Step-by-step explanation:
We have to find the range and interquartile range of the data below :
13, 14, 15, 18, 19, 19, 19, 20
Range: The range of set of data is the difference between the highest and the lowest values of the data set.
Range = Highest value - lowest value
Range = 20 - 13 = 7
Interquartile range (IQR): To find the IQR first we find the median of the data set.
13, 14, 15, 18, 19, 19, 19, 20
Median = (18 + 19)/2 = 18.5
= 18.5
Now we calculate the median of first half of the data set to find
13, 14, 15, 18
= (14 + 15)/2 = 14.5
and then calculate the median of second half of the data set to find 
19, 19, 19, 20
= (19 + 19)/2 = 19
IQR =
- 
IQR = 19 - 14.5 = 4.5
Range = 7
IQR = 4.5