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

某班的學習按考試成績分為60分以下，60-70，70-80，80-90，90-100，這種分組（）

某企業(yè)2018年技術工占50%，2019年新招收了一批學徒工，使學徒工的比重增加了10%。假定全廠各級工資水平均無變化，則2019年職工總平均工資將（）

品合格率指標是（）

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 （）.

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？

最能反映離散程度的指標是（）

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 （）.

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 （）.