One advantage of a stem and leaf plot over a frequency distribution is that （）.

對全國各鐵路交通樞紐的貨運量、貨物種類等進行調(diào)查，以了解全國鐵路貨運概況。這種調(diào)查屬于（）

某班的學習按考試成績分為60分以下，60-70，70-80，80-90，90-100，這種分組（）

如果居民按報告期價格購買商品需多支出40萬元，報告期商品銷售額為200萬元，則價格指數(shù)為（）

The number of class intervals in a frequency distribution is usually between （）.

A summary measure that is computed from a sample to describe a characteristic of the population is called（）

The number of phone calls arriving at a switchboard each hour has been recorded and the following frequency distribution has been developed.What is the approximate range of the number of phone calls arriving each hour？（）

什么是季節(jié)變動？研究它的意義何在？如何測定季節(jié)變動？

The number of phone calls arriving at a switchboard each hour has been recorded and the following frequency distribution has been developed.What is the cumulative frequency of the third class？（）

要了解某地區(qū)全部大學生的就業(yè)情況，那么（）