A summary measure that is computed from a sample to describe a characteristic of the population is called（）

一個地區(qū)一定時期的商品零售額屬于（）

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 cumulative frequency of the third class？（）

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

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 （）.

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). 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 cumulative frequency distribution would provide（）.

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

某廠某年職工勞動生產(chǎn)率為20000元，是歷史最高水平的1.2倍。這里的1.2倍是（）