1. People take you more seriously
2. At work, someone walks into a conference room chewing gum loudly dressed in a rpped jean shorts and a ripped t-shirt. Are you going to take them seriously?
3.When you're dressed for the job, you can do the job
4. being dressed for the job and looking, sounding, and acting like you are capable of doing the job well, people will know or think you can do whatever it is and you have a way better chance of getting hired
5. All of the above