Statistically essential? (5)

I believe the answer is:

vital

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'essential?' is the definition.
('vital' can be similar in meaning to 'essential')

I cannot understand how the remainder of the clue works.

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(Other definitions for vital that I've seen before include "Essential to life or critically important" , "Are such statistics" , "Absolutely necessary or life-giving" , "Critical, necessary" , "Essential; lively" .)

I've seen this clue in the Evening Standard.

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