Known as or to be

Test Preparation SAT Preparation
1

Hi,

This seems to be tested time and again in SAT tests. Is the correct idiom “known as” or “known to be”? I always thought it was “known as” but the following question’s answer is E, No Error.

No one [but] a fool would [readily] lend money to a person who [is known] [to be] a frequent gambler. [No error]

2

Known to be sounds correct to me.

http://talk.collegeconfidential.com/sat-preparation/547290-known-as-vs-known-to-be.html

It’s not wrong…so I guess that’s what matters? Hopefully someone else can provide input.