Balls!

Beach balls, that is. Ready for the daily Brain Bender (via the handy dandy discount MENSA calendar)??

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There was a contest to guess the number of beach balls in a store display. Fiona guessed 35, Gretchen guessed 28, Hope guessed 31, Inga guessed 34 and Jenny guessed 30. One was off by 5, one was off by 2, one was off by 1, one was off by 4 and one was correct.

How many beach balls were in the display?

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Huh. No clue here - math isn't my shtick. But you know what to do! Like always the answer will be found later in the comments. See you then!