一個(gè)地區(qū)一定時(shí)期的商品零售額屬于（）

A cumulative frequency polygon is also called （）.

在組距數(shù)列中，下限就是（）

對(duì)全國(guó)各鐵路交通樞紐的貨運(yùn)量、貨物種類(lèi)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（）

Which of the following is not the goal of descriptive statistics?（）

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 （）.

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

最能反映離散程度的指標(biāo)是（）

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 approximate range of the number of phone calls arriving each hour？（）