Premise:
"USDA's APHIS had experimented with several approaches to accepting and posting electronic comments on about 10 different proposed rules in recent years."
Hypothesis: Several approaches were experimented by USDA's APHIS.

yes

Premise:
"Call Las Vegas a Far West Tiger, and you wouldn't be too far off the mark."
Hypothesis: Las Vegas is deadly.

it is not possible to tell

Premise:
"The Ponte Vecchio is the most picturesque place to shop for pricey but gorgeous gold and silver jewelry, designed with centuries of learned expertise."
Hypothesis: Ponte Vecchio is where you will find the world's finest jewelry.
it is not possible to tell