一個地區(qū)一定時期的商品零售額屬于（）

如果居民按報告期價格購買商品需多支出40萬元，報告期商品銷售額為200萬元，則價格指數為（）

要了解某地區(qū)全部大學生的就業(yè)情況，那么（）

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 （）.

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？（）

A cumulative frequency polygon is also called （）.

變量數列中，各組頻率之和應（）

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

在組距數列中，下限就是（）

某企業(yè)的生產計劃完成百分比采用如下分組，請指出哪項是正確的（）