A: In a scientific experiment, a confounding variable is a secondary, changing condition that muddies the experimenter's hypothesized inference between cause and effect. Researchers must be meticulous about experiment design to control for confounding variables and to protect the integrity of their findings.
Fairfax County, officially the County of Fairfax, is a county in the Commonwealth of Virginia. As of the 2010 census, the population was 1,081,726, in 2014, the population was estimated to be 1,118,883, making it the most populous jurisdiction in the Commonwealth of Virginia, with 13.6% of Virginia's population.lexandria County was returned to Virginia in 1846, reduced in size by the secession of the independent city of Alexandria in 1870, and renamed Arlington County in 1920. The Fairfax County town of Falls Church became an independent city in 1948.
As of 2014, the population was 24,483. It is the county seat of Fairfax County. Although it is an enclave of Fairfax County, the two are separate political entities. Situated in Northern Virginia, Fairfax is part of the Washington-Arlington-Alexandria, DC-VA-MD-WV Metropolitan Statistical Area.Fairfax is 16 miles (25 kilometers) southwest of Washington, D.C. Washington Metro's Orange Line serves Fairfax through its Vienna Station.airfax County's Government Center is west of the City of Fairfax. Fairfax County contains an exclave located in the central area of the City of Fairfax, in which many county facilities (including the courthouse and jail) are located.