takes about 5month
The minimum income requirements for family sponsorship under the 2010 Poverty Guidelines issued by U.S. Citizenship and Immigration Services for the 48 contiguous states, the District of Columbia, Puerto Rico, the U.S. Virgin Islands, and Guam are:
2 $18,212
3 $22,887
4 $27,562
5 $32,237
6 $36,912
7 $41,487
8 $46,262
link:: http://www.uscis.gov/files/form/i-864p.pdf