You get a large sample of people, in this particular study,

这个研究需要你先找到大量试验样本
each dot represents a subject in here

每个点都代表一个实验对象
and you take their body mass index,

你只需要知道目标人群的身高和体重
just by knowing their height and weight

就能算出他们的体重指数了
and you see how carefully it represents body fat.

然后你就可以清晰看到体脂肪的图形了
The women are in the lighter colored, the orange colored squares

亮色是代表女性就是橘色区域
and the men are in the blue colored ovals.

蓝色点代表男士
The lines here show that--several things.

这几条线各自表示不同的意义
This is the average for the women,

这条线表示女性的均值
the line that goes right through there;

这条线一直延伸到那里
this would be the average for the man that goes through there.

另一条是男性的均值一直延伸到那里
What you see is a pretty nice relationship that,

你能看出它们之间精确的关系