Which of the following statements is not true？（）

對某班級學(xué)生的生活狀況進行統(tǒng)計調(diào)查，下列標(biāo)志中屬于不變標(biāo)志的是（）

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). 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 （）

A cumulative frequency distribution would provide（）.

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 cumulative frequency of the third class？（）

某企業(yè)的生產(chǎn)計劃完成百分比采用如下分組，請指出哪項是正確的（）

A cumulative frequency polygon is also called （）.

時間序列構(gòu)成因素有哪些？分解的基本原理和思路是什么？