are a new class of decision support systems which help businesses discover subtle and complex relationships hidden in their data.

answer; sales of books;

since the options are not listed, when you are working on your budget you should also add water, tv, internet, miscellaneous and your 'fun' money for in your budget. when budgeting, you need to allow for fun money, and mis/accidental money so that you stick to the budget and not go crazy because you feel strapped to the budget.

consumer credit. an advantage is that it allows consumers to afford expensive goods and services now, increasing their standard of living. however, a disadvantage is that it creates a trap for debt, if people do not have self control, they may see themselves filing personal bankruptcy.