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 $$446,200.$

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 $$164,800,$ and Shirley earns wages of $$247,200.$

Their additional Medicare tax is $fill in the blank $2$

$.$

c$.$ Simon has net investment income of $$51,000$ and MAGI of $$255,000$ and files as a single taxpayer.

Simon's additional Medicare tax is $fill in the blank $3$

$.$