Job Interview Questions: How to do my hair for a job interview tomorrow?

I have long (an inch or two below my shoulders), thick, completely straight medium-brown hair. I also have a job interview tomorrow for an accounting firm. I am 21, but I look like I'm still in high school. (people ask me if I'm home schooled when I go shopping during school hours.)
How should I do my hair for a professional job interview tomorrow? I was thinking just a low pony tail, but is that too informal? Help please!

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Recommended Answer:
I would try a mature hairstyle, a low ponytail could work, but add a little something. Make a low pony, but leave a small section of hair out under the elastic. Wrap that strand then around the elastic for a more sophisticated look. I would just try something that could get you to look older or your age.

help me out too!

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