数学术语”less-than cumulative frequency"

cumulative frequency distribution是什么意思 请问统计学中的cumulative frequency怎样做? less than more than? no less than .not less than 不同点. 小于是be lesser than还是be less than数学用语 fewer than 与less than? less than 和 fewer than more than 和less than less-than-good 是什么意思? Less healthy than 是什么意思 less/more than 造句 ____is less than ___