Pleural cavity: the cavity in the thorax that contains the lungs. Source: WordNet 2.1. Pleural cavity: cavity within the thoracic cavity consisting of the space between the parietal and visceral pleura; normally contains a capillary layer of serous fluid that lubricates the pleural surfaces.
Middle Class Average Income Range: $36,000 â $57,657. On a narrow view, a middle class family is said to have a mean average household income of $46,829 on a yearly basis. The numbers reflected on the 2010 Census showed that middle class average yearly income range from $36,000 â $57,657. Such figures fall on the third quintile.
The income it takes to be middle-income varies by household size, with smaller households requiring less to support the same lifestyle as larger households, Pew explains. Here's the breakdown of how much you have to earn each year to qualify as middle-income, depending on the size of your family: Household of one: $24,042 to $72,126. Household of two: $34,000 to $102,001. Household of three: $41,641 to $124,925