4. Tax Computations. (Obj. 1) Compute the taxable income and income tax liability (before credits) for each of the following taxpayers. Each taxpayer uses the standard deduction.

a. A widowed taxpayer, age 30, has one dependent. Her filing status is qualifying widow(er); AGI is $46,400.

b. An unmarried taxpayer, age 74, has no dependents and AGI of $19, 590.

c. A taxpayer, age 40, is married but files a separate return from his spouse. The taxpayer is the noncustodial parent of his 8-year-old child. His wife has signed Form 8832 giving him the right to claim their daughter as a dependent. AGI is $130,580.

d. An unmarried taxpayer, age 72, is claimed as a dependent on her sons return. Her AGI consists solely of $3,150 of taxable interest.

e. A married couple, ages 67 and 66, file a joint return. They claim one dependent. AGI is $161,555.