22% of American Jews are agnostic or atheist. If you include reformed Judaism who believe in God (of the Tanakh) but aren't too observant or practicing, what you might call the Jewish equivalent of the "lapsed Catholic", it goes to well over 1/3.
One reason Jews are overrepresented in professional careers is because they have LONG tradition of literacy as more than just a good thing but rather a duty or obligation of Jews. Primarily, the end-purpose of this duty to literacy was for religious education and study. i.e. so that all Jews could read their Bible, rabbinical teachings and decrees, and that sort of thing. But obviously, once you have a tradition of literacy, it lends very easily beyond religious tracts.
Still, the orthodox and especially the ultra-orthodox can be highly literate in matters of religious study (e.g. the Talmud, rabbinical teachings, etc) but often are fairly deficient in secular subjects. Israel has a significant population of orthodox and ultra-orthodox Jews living on the dole, at or below the poverty line, who basically do not work. They just hang around synagogues, praying, mentoring young Jews, reading the Talmud or whatever, participate in community affairs, like church deacons or elders but not actual rabbinical clergy. And of course, have lots of children.
