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

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 （）.

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？

變量數列中，各組頻率之和應（）

常用的長期趨勢測定的方法有哪些？各有什么特點？

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，則價格指數為（）

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

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

品合格率指標是（）

Descriptive statistics deals with methods of（）