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 （）.

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（）

某廠某年職工勞動(dòng)生產(chǎn)率為20000元，是歷史最高水平的1.2倍。這里的1.2倍是（）

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 （）.

常用的長(zhǎng)期趨勢(shì)測(cè)定的方法有哪些？各有什么特點(diǎn)？

某企業(yè)2018年技術(shù)工占50%，2019年新招收了一批學(xué)徒工，使學(xué)徒工的比重增加了10%。假定全廠各級(jí)工資水平均無(wú)變化，則2019年職工總平均工資將（）

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（）

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？（）

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

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？（）