Answer:
Interquartile Range
The interquartile range of an observation variable is the difference of its upper and lower quartiles. It is a measure of how far apart the middle portion of data spreads in value.
Interquartile Range = U pper Quartile − Lower Quartile
Problem
Find the interquartile range of eruption duration in the data set faithful.
Solution
We apply the IQR function to compute the interquartile range of eruptions.
> duration = faithful$eruptions # the eruption durations
> IQR(duration) # apply the IQR function
[1] 2.2915
Answer
The interquartile range of eruption duration is 2.2915 minutes.
Exercise
Find the interquartile range of eruption waiting periods in faithful.
Explanation: