The difference in names is generally not big, but sometimes it can be seen from the surname. For example, people with the surname Smith are usually black.
Generally, the average white family has less than 2 children, the Asian family has a little more than 2 children, and the black family has the most children, with an average of almost 3. Also, generally the richer the family, the fewer children they have. Also, among white people, Jewish families also have many children. In addition to black people, who have many children, there are also many children from Spanish-speaking families.
Your friend has 9 brothers and sisters in his family, and black people have the greatest chance.