G'day mates!

Today I have two questions:

1) I have a large dataset, containing people's social security numbers and their income. No I want to select e.g. two percent of the people in the table AT RANDOM, and change their income by 10 percent. How do I accomplish this?

2) Depending on what income, and the social status (married, divorced, etc.) the people above have, I want to give them a certain score. I have (on paper) a list of which income interval and social status goes with which score. Now I want to take the income variable in the table in 1), compare with my "lookup table", and assign the apropriate score to evey person. How do I do this the best way? Do I use a lot of IF:s? Or can I create a table containing income intervals, social status and the corresponding score, and look up values in some clever way?

Thanks lots!