什么是季節(jié)變動？研究它的意義何在？如何測定季節(jié)變動？

企業(yè)生產一種產品需順次經過四個車間，這四個車間的廢品率分別為1.5%、2.0%、2.0%和1.0%。該企業(yè)生產這種產品的平均廢品率是多少？

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 （）.

A student achieves an 82 on the first test in a statistics course. From this, she assumes that her average at the end of the semester (after other tests) will be about 82. This is an example of （）.

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（）

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（）

常用的長期趨勢測定的方法有哪些？各有什么特點？

在組距數列中，下限就是（）

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 （）.

變量數列中，各組頻率之和應（）