Hi, Arisleidy,
The thesis statement is your answer to the posed question. It is a concise claim that you will expand upon in the body of your paper. Most often, it will appear as the last sentence of your introductory paragraph.
It seems that the question posed to you was this: Is college worth the cost? The use of the word "how" in your post on WyzAnt leads me to believe that you think college is, in fact, worth the cost. So, think of three reasons why. Your thesis statement will contain those three reasons in brief. It will look something like this:
"College is worth the cost because x, y, and z."
Now, in the body of your paper, discuss x first, y second, and z third. And don't forget to follow all of that with a concluding paragraph that summarizes what you discussed.
I'd be happy to help you more specifically with your thesis statement and the entire paper. Contact me to set up a private tutoring session. I look forward to helping you succeed!
Sincerely,
Miss Mary