Compute the additional Medicare tax for the following taxpayers. If required, round your answers to the nearest dollar.

a. Mario, who is single, earns wages of $472,600. His additional Medicare tax is $fill in the blank 1.

b. George and Shirley are married and file a joint return. During the year, George earns wages of $298,100, and Shirley earns wages of $447,150. Their additional Medicare tax is $fill in the blank 2.

c. Simon has net investment income of $56,320 and MAGI of $281,600 and files as a single taxpayer. Simon's additional Medicare tax is $fill in the blank 3.