Final answer:
Medicare spending, Social Security spending, and changes in the tax rate are examples of fiscal policy measures. Fed purchases of Treasury securities are not an example of fiscal policy.
Step-by-step explanation:
Fiscal policy refers to the government's use of spending and taxation to influence the economy. Medicare spending, Social Security spending, and changes in the tax rate are examples of fiscal policy measures.
However, Fed purchases of Treasury securities are not an example of fiscal policy. These purchases are conducted by the Federal Reserve, which is the central bank of the United States, and are part of monetary policy, which focuses on managing interest rates and the money supply.