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

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

Descriptive statistics deals with methods of（）

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

常用的長期趨勢測定的方法有哪些？各有什么特點(diǎn)？

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 （）.

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

某班的學(xué)習(xí)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 statements is not true？（）

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