Don't believe numbers. They can be 'rearranged' to suit the claimer's needs.

Let's say I study 100 people. It's on a college campus, so 50 out of the 100 people admit to smoking cannabis regularly. I could claim that 1 out of every 2 college students smokes cannabis. That's fine. Nothing wrong with that. Buuuut...

4 students admit to committing crimes that are cannabis-related. Robbery to get money to buy weed, drug dealing to minors, etc. Now...

I could make 45 of the original 50 admitted cannabis smokers simply 'disappear'. And then I could reasonably claim that 4 out of every 5 pot smokers admit to committing crimes. Essentially, I'm telling the truth because those people did admit to committing crimes. BUT I'm making the other 45 people disappear because I simply can.

They're NOT lying to you. They're just not telling the entire truth, either...

If my explanation was confusing please let me know and I'll expand upon it.