You can take a quiz that includes 15 questions from the survey here. If this is really representative, the quiz wasn't all that hard, but on the other hand it does include questions like "What is the religion of most people in Pakistan" that are not really tests of religious knowledge. The whole test is here.
I was intrigued by how the respondents identified their own religion. A majority were Protestants, at 52%, 24% were Catholic, and 16% were "unaffiliated," of whom 3% were agnostics, 1% atheists, and 12% "Nothing in Particular."
I thought the most disturbing finding was in the answers to this question:
Are public school teachers permitted to read from the Bible as an example of literature?Of course the correct answer is "yes", but only 23% got this one right and 67% said "no." American Christians really do worry that the government is hostile to them.