My macroeconomics class wants me to explain the discrepancies between the unemployment rates of Black males and everyone else...

See it is things like this that contribute to my militant nature, they are just asking me to rant. It says that: 

As of July 2007

National Unemployment Rate 4.6%
White Unemployment Rate 4.3%
Black Unemployment Rate 8.9%
Hispanic/Latino Unemployment Rate 6.0%
Asian 3.0%

Then they want me to do the following: What do you think can explain these discrepancies? Please describe at least TWO different theories for this unemployment discrepancy  Use information from your text as well as outside sources to corroborate your theories.

I don’t need my book to explain any of that.