All 3 Uses

hypothesis
in
Outliers
(Edited)

At one point I asked Langan, hypothetically, whether he would take a job at Harvard University were it offered to him.
Chpt 4 *

hypothetically = based on something that is temporarily treated as true to advance a discussion or to further investigation
The "culture of honor" hypothesis says that it matters where you're from, not just in terms of where you grew up or where your parents grew up, but in terms of where your great-grandparents and great-great-grandparents grew up and even where your great-great-great-grandparents grew up.
Chpt 6 *

hypothesis = a seemingly reasonable, but unproven, idea
The linguists Ute Fischer and Judith Orasanu once gave the following hypothetical scenario to a group of captains and first officers and asked them how they would respond: ...
Chpt 7

hypothetical = something temporarily treated as true to advance a discussion or to further investigation

Definitions:

(1) (hypothesis as in: a study to test her hypothesis)
a seemingly reasonable, but unproven idea or explanation based upon known facts

In casual conversation, theory is a synonym for hypothesis, but a scientist would say that a hypothesis needs to pass rigorous tests before it could be accepted as a theory.
(2) (hypothesis as in: assume as a working hypothesis)
something that may or may not be true, but is temporarily treated as true to advance a discussion or to further investigation

This sense of hypothesis is typically seen in the form, hypothetical, or hypothetically.
(3) (meaning too rare to warrant focus)