When you refinance to a lower rate, that reduces the size of your mortgage interest deduction, which affects your savings from refinancing. The Mortgage Refinance Calculator can take that into account, which is why it asks for your income tax rate.
Look up yo in Wiktionary, the free dictionary. Yo is an English slang interjection, commonly associated with American English. It was popularized after being used commonly by the Italian-American community in Philadelphia, Pennsylvania since the 1940s.
6. yo. A word who's origin is made to be puzzling, but is really made famous by the Movie Rocky and by various rappers. Yo is a word deeply connected in the Philadelphia culture, therefore; no, it is not used only by little black kids or wannabe suburbans like the definitions before it has stated.