Here’s some advice:

Here’s some advice: At a job interview, tell them you’re willing to give 110 percent. Unless the job is a statistician.

The humor in this joke derives from the fact that a single person cannot give 110% of their effort, since that is impossible. There is only 100% of anything, and any more than that would have to involve having more than one person. The interviewer who is a statistician would be expected to know that (and take it literally).

Really, I don't think that most jobs should expect for someone to give more than ~33%, since you are expected to sleep for 8 hours, work for 8 hours, and then be home (or commuting) for 8 hours.

This joke also works for mathematicians, as a side note.