Descriptive statistics deals with methods of（）

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

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？（）

常用的長期趨勢測定的方法有哪些？各有什么特點(diǎn)？

企業(yè)生產(chǎn)一種產(chǎn)品需順次經(jīng)過四個(gè)車間，這四個(gè)車間的廢品率分別為1.5%、2.0%、2.0%和1.0%。該企業(yè)生產(chǎn)這種產(chǎn)品的平均廢品率是多少？

一個(gè)地區(qū)一定時(shí)期的商品零售額屬于（）

什么是季節(jié)變動(dòng)？研究它的意義何在？如何測定季節(jié)變動(dòng)？

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

變量數(shù)列中，各組頻率之和應(yīng)（）

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？