Background: Irving Fisher (February 27, 1867 - April 29, 1947) was an American economist, statistician, inventor, and Progressive social campaigner. He was one of the earliest American neoclassical economists, though his later work on debt deflation has been embraced by the Post-Keynesian school. Joseph Schumpeter described him as "the greatest economist the United States has ever produced", an assessment later repeated by James Tobin and Milton Friedman. Fisher made important contributions to utility theory and general equilibrium.
Context: James Tobin argued that the intellectual breakthroughs that marked the neoclassical revolution in economics occurred in Europe around 1870. The next two decades witnessed lively debates, which led to the new theory being more or less incorporated into the classical tradition that preceded it. In the 1890s, according to Joseph A. Schumpeter there emerged  A large expanse of common ground and ... a feeling of repose, both of which created, in the superficial observer, an impression of finality - the finality of a Greek temple that spreads its perfect lines against a cloudless sky. Of course, Tobin argues, the temple was by no means complete. Its building and decoration continue to this day, even while its faithful throngs worship within. American economists were not present at the creation. To a considerable extent they built their own edifice independently, designing some new architecture in the process. They participated actively in the international controversies and syntheses of the period 1870-1914. At least two Americans were prominent builders of the "temple," John Bates Clark and Irving Fisher. They and others brought neoclassical theory into American journals, classrooms, and textbooks, and its analytical tools into the kits of researchers and practitioners. Eventually, for better or worse, their paradigm would dominate economic science in this country.  In reviewing the history of utility theory, economist George Stigler wrote that Fisher's doctoral thesis had been "brilliant" and stressed that it contained "the first careful examination of the measurability of the utility function and its relevance to demand theory." While his published work exhibited an unusual degree of mathematical sophistication for an economist of his day, Fisher always sought to bring his analysis to life and to present his theories as lucidly as possible. For instance, to complement the arguments in his doctoral thesis, he built an elaborate hydraulic machine with pumps and levers, allowing him to demonstrate visually how the equilibrium prices in the market adjusted in response to changes in supply or demand.
Question: Where was he when he came up with the theory?
Answer: 

Background: George Washington (February 22, 1732 - December 14, 1799) was an American statesman and soldier who served as the first President of the United States from 1789 to 1797 and was one of the Founding Fathers of the United States. He served as Commander-in-Chief of the Continental Army during the American Revolutionary War, and later presided over the 1787 convention that drafted the United States Constitution. As a driving force behind the nation's establishment he came to be known as the "father of the country," both during his lifetime and to this day. Washington was born into the provincial gentry of Colonial Virginia to a family of wealthy planters who owned tobacco plantations and slaves, which he inherited.
Context: George Washington was the first child of Augustine Washington and his second wife Mary Ball Washington, born on their Popes Creek Estate near Colonial Beach in Westmoreland County, Virginia. He was born on February 11, 1731, according to the Julian calendar and Annunciation Style of enumerating years then in use in the British Empire. The Gregorian calendar was adopted within the British Empire in 1752, and it renders a birth date of February 22, 1732.  Washington was of primarily English gentry descent, especially from Sulgrave, England. His great-grandfather John Washington immigrated to Virginia in 1656 and began accumulating land and slaves, as did his son Lawrence and his grandson, George's father Augustine. Augustine was a tobacco planter who also tried his hand at iron manufacturing, and later he was the Justice of the Westmoreland County Court. In Washington's youth, his family was moderately prosperous and considered members of Virginia's "country level gentry" of "middling rank," rather than one of the leading wealthy planter elite families. His wife Sally was also a friend of Washington and an early romantic interest, and maintained correspondence when she moved to England with her father, but most of the letters were intercepted by the British during the war.  Lawrence Washington inherited a plantation from their father on the Potomac River at Little Hunting Creek which he named Mount Vernon in honor of his commanding officer Vice Admiral Edward Vernon. Washington inherited Ferry Farm upon his father's death and eventually acquired Mount Vernon after Lawrence's death.  The death of his father prevented Washington from an education at England's Appleby Grammar School such as his older brothers had received. He achieved the equivalent of an elementary school education from a variety of tutors, as well as from a school run by an Anglican clergyman in or near Fredericksburg. His education totaled seven or eight years, while he lived with relatives at various places that included the Westmoreland and the Chotank regions of Virginia, as well as Ferry Farm and Mount Vernon. He was trained in mathematics, trigonometry, and surveying that developed a natural talent of draftsmanship and map making. He was also an avid reader and purchased books on military affairs, agriculture, and history, as well as the popular novels of his times. There was talk of securing an appointment for him in the Royal Navy when he was 15, but it was dropped when his widowed mother objected.  In 1751, Washington traveled with Lawrence to Barbados (his only trip abroad) in the hope that the climate would be beneficial to Lawrence's declining health, as he was suffering from tuberculosis. Washington contracted smallpox during the trip, which left his face slightly scarred but immunized him against future exposures to the disease. Lawrence's health failed to improve, and he returned to Mount Vernon where he died in the summer of 1752. His position as Adjutant General (militia leader) of Virginia was divided into four district offices after his death, and Washington was appointed by Governor Dinwiddie as one of the four district adjutants in February 1753, with the rank of major in the Virginia militia. He also became a freemason while in Fredericksburg during this period, although his involvement was minimal.
Question: Did he have any siblings?
Answer:
the first child