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？（）

時間序列構成因素有哪些？分解的基本原理和思路是什么？

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

Descriptive statistics deals with methods of（）

為什么在計算平均指標的基礎上還有必要進一步計算變異指標？

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 （）.

品合格率指標是（）

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

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

以2000年a0為最初水平，2016年an為最末水平，計算鋼產(chǎn)量的年平均發(fā)展速度時，須開（）