you can run through it also, just putting 0's in for withholdings to date in 1995, and it ends up giving you your estimated taxes.

you are correct that the marginal tax rate is 15%.  But that is the number you use to calculate how much more tax you would pay on earning an additinion, say, $1000 over your base earnings--a very useful number, but not for estimating your total tax bill--only your marginal taxes.

there are some deductions that Mimi (and most of us) would get before the tax calculations would apply, according to the way she describes herself--kind of a personal deduction and what's called a standard deduction.  It more or less means that roughly the first $10,000 is taxed at 0%.  (these calculations are buried in that withholding calculator I directed you to above, but if you dig a little on the IRS site, doubt you'll want to as it's unbelievable boring, you'll see the detail of this).  then, I'm going a little from memory, the next $7500ish is taxed at 10%.  So in her case the only money taxed at the higher marginal 15% rate is the amount above the $17,500ish.  So her tax bill comes out to be pretty small.  And of course i don't know anything else about her life, but she may have some other deductions that would lower this--she sounds like someone that would donate to good charitable causes for example, or maybe pay interest on some student loans, maybe some work expenses.

oh and the way I read mimi, she supports herself more than 50%, and she would therefore get some benefit from being a household filer rather than a single filer.  Her parents I believe, would have to be giving her another $20,000+ before they could claim her as a deduction.

hope that helps  :)