A cumulative frequency polygon is also called （）.

以2000年a0为最初水平，2016年an为最末水平，计算钢产量的年平均发展速度时，须开（）

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？（）

A cumulative frequency distribution would provide（）.

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

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 politician who is running for the office of premier in a state with 3 million registered voters commissions a survey. In the survey, 53.6% of the 5000 registered voters interviewed say they plan to vote for him. The population of interest is the（）

Which of the following is best to show the percentage of a total budget that is spent on each category of items？（）

Descriptive statistics deals with methods of（）

某班的学习按考试成绩分为60分以下，60-70，70-80，80-90，90-100，这种分组（）