If data are grouped into intervals and the number of items in each group is listed, this could be called a （）

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（）

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（）

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

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

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

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 （）.

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（）

變量數(shù)列中，各組頻率之和應(yīng)（）

One rule that must always be followed in constructing frequency distributions is that （）.