15-Letter Words Matching _R_P___________

There are 20 15-letter words that match _R_P___________. 4 are common words, such as PREPOSITIONALLY and PROPORTIONALITY. A rarer one is TRYPANOSOMIASES. In this set, I is the most frequent open letter (19 words). 5 words contain a doubled letter.

Full list 20

prepositionallyproportionalityproportionatelyproprietorshipscryptanalyticalpreprofessionalproprietoriallyproprioceptionstrypanosomiasiscryptorchidismscryptozoologiescryptozoologistgraphitizationspreperformancespreponderanciespreponderationsprepresidentialprepublicationsproportionatingtrypanosomiases

About this list

Words
20 (4 common words)
Common example
prepositionally
Rare example
trypanosomiases
Doubled letters
5
Ending in S
11
Most frequent letter
I (19)

Questions

How many 15-letter words matching _r_p___________ are there?

20. 4 of them are common words.

What is a common example?

PREPOSITIONALLY is among the common words in this set.