Premise:
"The apparent going premium of 50 percent for a targeted ad on the Internet suggests that Internet advertising may be as likely to reduce total ad spending as to increase it."
Hypothesis: Many organizations are switching to Internet ads for increased sales.

it is not possible to tell

Premise:
"There is a potential that we're exposing workers to increased health risks."
Hypothesis: Our employees are guaranteed to be safe.

no

Premise:
"you put five Soviet Hyundee helicopters in the air they can level the entire area and there won't be anything left alive and they can do that in about four minutes"
Hypothesis: The helicopters flew at 5000 feet.
it is not possible to tell