This is a hard question to quantify. I suspect so. No one bothers to check facts. It is much easier to check what is written.
I'm currently in need of checking out health care claims made by alternate medicine. For the fifth time, I have checked the math of their claims and found what sounds like a scientific study to contain faulty math and the math was not much more complicated than %s.
What does that mean? It means that the paper was not peer read. (Other people in the same field didn't read it). Now let me ask you a question. If a product made claims about what it sold and it used faulty stats, would you buy the product? And yet these people do millions of dollars worth of sales a year. Someone must believe them.
Do you believe the news delivered by Fox or CNN. I live in Canada. 2 years ago we were in the states and someone shot up our house of commons and the grounds killing at least 2 people. It made a huge story for CNN: they claimed that it was a terrorist attack. They kept the story going for hours. It was their number one headline that day. It turns out that one of the people killed was a security guard (unarmed in Canada he is employed to keep dogs off the grass). I tried to tell the people we were staying with that was a bogus story. They thought it was real. The next day the truth came out. CNN made no mention of the real story. They just moved on.
Yes many people believe what they are told or they read. Seems the power of the written word has not lessened, and people do not want to check the facts. There are just too many facts to check.