Which of the following is best to show the percentage of a total budget that is spent on each category of items？（）

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 （）.

最能反映離散程度的指標(biāo)是（）

為什么在計(jì)算平均指標(biāo)的基礎(chǔ)上還有必要進(jìn)一步計(jì)算變異指標(biāo)？

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？（）

對(duì)全國(guó)各鐵路交通樞紐的貨運(yùn)量、貨物種類等進(jìn)行調(diào)查，以了解全國(guó)鐵路貨運(yùn)概況。這種調(diào)查屬于（）

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（）

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？（）

一個(gè)地區(qū)一定時(shí)期的商品零售額屬于（）

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