The average size is 3,131 square feet, with a standard deviation of 655 square feet. (Standard deviation is a statistical measure of variance.)

平均大小为 3,131 平方英尺，标准偏差为 655 平方英尺（标准偏差是一个描述差异的统计量度）。

youdao

Measure a person's general ability; then measure their cleverness, then square both numbers and add them together, then take the square root.

衡量人们的总体能力，然后衡量他们的聪明度，算出两个数字的平方，再把它们相加，最后求出平方根。

youdao

There were no chemical or biological weapons with the containerized labs, which measure 20 feet square.

CNN: U.S.: Mobile labs found in Iraq

Typical closets in the complex measure around 400 square feet, and were meant to appeal to buyers who might be moving into a condo from a large home, says director of design and development Eric Jencks.

WSJ: The $100,000 Closet

The cages, stacked on top of each other, measure 1.5 square meters (16 square feet).

NPR: Hong Kong Poor Living In Cages And Cubicles