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 （）.

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？（）

什么是季节变动？研究它的意义何在？如何测定季节变动？

Which of the following statements is not true？（）

要了解某地区全部大学生的就业情况，那么（）

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（）

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（）

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

Claudia Taylor, Director of Global Industrial Sales in Melbourne, is concerned by a deteriorating sales trend. Specifically, the number of customers is stable at 1500 but they are purchasing less each year. She orders her staff to search for causes of the downward trend by selecting a focus group of 40 industrial customers. For this study, the set of 40 industrial customers is a （）.

某厂某年职工劳动生产率为20000元，是历史最高水平的1.2倍。这里的1.2倍是（）