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 cumulative frequency of the third class？（）

某企業(yè)的生產計劃完成百分比采用如下分組，請指出哪項是正確的（）

品合格率指標是（）

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？（）

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（）

One advantage of a stem and leaf plot over a frequency distribution is that （）.

某班的學習按考試成績分為60分以下，60-70，70-80，80-90，90-100，這種分組（）

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 （）.