interquartile range vs middle fifty

interquartile range and middle fifty both are nouns.

Word	Noun	Adjective	Verb	Adverb
interquartile range	Yes	No	No	No
middle fifty	Yes	No	No	No

As nouns, interquartile range and middle fifty are synonyms defined as:

interquartile range and middle fifty: a measure of statistical dispersion, being equal to the difference between the upper and lower quartiles.

Other synonyms of interquartile range include midspread.

interquartile range (noun)	middle fifty (noun)
a measure of statistical dispersion, being equal to the difference between the upper and lower quartiles.	a measure of statistical dispersion, being equal to the difference between the upper and lower quartiles.