變量數(shù)列中，各組頻率之和應（）

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

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 （）.

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

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

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？

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（）

Which of the following is not the goal of descriptive statistics?（）

If the individual class frequency is divided by the total frequency, the result is the （）.

在組距數(shù)列中，下限就是（）