1 Intracellular fluid (2/3 of body water). 2  Per Guyton, in a body containing 40 litres of fluid, about 25 litres is intracellular, which amounts to 62.5% (5/8), close enough to the 2/3 rule of thumb. 3  Jackson's texts states 70% of body fluid is intracellular. 4  Extracellular fluid (1/3 of body water).
However, if you provided support to your brother, depending on the level of support and your brotherâs gross income for 2010, you may be able to claim him as a dependent on your tax return (under the qualifying relative rules).
Niece or Nephew. Your brother's 12-year old daughter lived with you for 7 months out of the year. You, your brother, and your father each provided some of her financial support during the year--but she provided none of her own support. Your niece meets the requirements to be your Qualifying Child, and you can claim her as a dependent.