Determine the amount of the standard deduction for each of the following taxpayers for tax year 2018: christina, who is single. adrian and carol, who are filing a joint return. their son is blind. peter and elizabeth, who are married and file separate tax returns. elizabeth will itemize her deductions. karen, who earned $1,100 working a part-time job. she can be claimed as a dependent by her parents. rodolfo, who is over 65 and is single. bernard, who is a nonresident alien with u. s. income. manuel, who is 70, and esther, who is 63 and blind, will file a joint return. herman, who is 75 and a qualifying widower with a dependent child.