Which of the following statements is not true？（）

變量數(shù)列中，各組頻率之和應(yīng)（）

Descriptive statistics deals with methods of（）

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 （）.

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

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？

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

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

對全國各鐵路交通樞紐的貨運量、貨物種類等進行調(diào)查，以了解全國鐵路貨運概況。這種調(diào)查屬于（）

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 approximate range of the number of phone calls arriving each hour？（）