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). Personnel records of 50 employees are selected for analysis. (The plant employs 250.) For this study, the average number days absent for these 50 employees is a （）.

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

品合格率指標(biāo)是（）

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？（）

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

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？

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（）

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

最能反映離散程度的指標(biāo)是（）

如果居民按報(bào)告期價(jià)格購(gòu)買商品需多支出40萬(wàn)元，報(bào)告期商品銷售額為200萬(wàn)元，則價(jià)格指數(shù)為（）