Learn Italian: Si studia questa statistica perché il dato è preoccupante. - One studies this statistic because the figure is worrying.

This sentence uses the passive si (si passivante) structure, which is much more common and natural in Italian than using a literal word for "one". Because questa statistica is the object receiving the action, the sentence is structured more like "This statistic is studied".

Does il dato mean "the date"?

No, that is a common false friend! A date on a calendar is la data. Il dato means "the piece of data", "the figure", or "the fact". Notice it is singular here; to talk about "the data" as a plural concept, you use i dati.

Since this lesson is about il che, could I use it in this sentence instead of perché?

No, because perché means "because", while il che means "which" when referring back to a whole previous statement. To use il che, you would have to flip the sentence's cause and effect. For example: Il dato è preoccupante, il che spiega perché si studia questa statistica (The figure is worrying, which explains why this statistic is studied).

Why does the adjective preoccupante end in -ante?