Hello, I like your post, your description is simple but accurate. The second example, your said your roommate looks like Korean, because he is Asian and had longer and curry hair, it tells me that you know some Korean people and you know their appearance, you also know your roommate’s gabby through his clothing. In the third example, you also gives a guess on a boy who uses expensive bags in school, he is showing his ability of spending, and then you take a guess on his family’s finical situation must be good. These guesses are based on your life experiences and I think they are reasonable.