A study published in Stroke last year involved about two thousand people with an average age of sixty-two.

VOA: special.2009.08.12

It reminds me of a joke about the statistician who drowned in a pool with an average height of 10 inches.

这让我想起一个统计学笑话,在一个平均水深为10英寸的游泳池里，谁会被淹死。

哈佛公开课 - 幸福课课程节选

American children now spend an average of seven and a half hours a day watching television or playing with electronic devices.

VOA: special.2010.06.07

Now,with the vision centers in place, doctors are treating an average of 5,000 patients per center per year.

VOA: standard.2010.05.25