If the individual class frequency is divided by the total frequency, the result is the （）.

對(duì)某班級(jí)學(xué)生的生活狀況進(jìn)行統(tǒng)計(jì)調(diào)查，下列標(biāo)志中屬于不變標(biāo)志的是（）

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

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？（）

One rule that must always be followed in constructing frequency distributions is that （）.

Simon Arnett, Director of Human Resources, is exploring the causes of employee absenteeism at Buderim Bottling during the last operating year (1 January 2005 to 31 December 2005). The average number of absences per employee, calculated from the personnel data of all employees, is a （）.

If data are grouped into intervals and the number of items in each group is listed, this could be called a （）

最能反映離散程度的指標(biāo)是（）

時(shí)間序列構(gòu)成因素有哪些？分解的基本原理和思路是什么？

要了解某地區(qū)全部大學(xué)生的就業(yè)情況，那么（）