You are supposed to know these values (together with the proper unit) for the semifinal and final exams.

Different labs may use different methods, so some variation is expected. Reference values may depend on sex, age, race or other factors. So these values are useful approximations, it is not worth to learn them exactly.

It is clear that an interval is necessary instead of a single value because of biological variability. Nowadays we prefer the term "reference interval" instead of the "normal interval" used previously. There are several reasons for this: on one hand we want to show, that you cannot expect to be able to determine if a person has a particular disease or not, by measuring a single laboratory parameter. On the other hand, we also avoid the use of the term "normal", which is very difficult to define.