Which of the following statements is not true？（）

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

某企業(yè)的生產(chǎn)計(jì)劃完成百分比采用如下分組，請(qǐng)指出哪項(xiàng)是正確的（）

One rule that must always be followed in constructing frequency distributions is that （）.

變量數(shù)列中，各組頻率之和應(yīng)（）

對(duì)全國(guó)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(guó)鐵路貨運(yùn)概況。這種調(diào)查屬于（）

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 （）.

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？（）

時(shí)間序列構(gòu)成因素有哪些？分解的基本原理和思路是什么？

某班的學(xué)習(xí)按考試成績(jī)分為60分以下，60-70，70-80，80-90，90-100，這種分組（）