问题 名词解释

点估计和区间估计

答案

参考答案:

点估计也叫定值估计,就是直接用抽样平均数代替总体平均数,用抽样成数代替总体成数。区间估计是在一定概率保证下,用样本统计量和抽样平均误差去推断总体参数的可能范围的估计方法

完形填空

下面是一篇文章,请将标有A—G的句子插入文章标号56-60的合适位置,使这篇文章意义完整,结构连贯;其中有两个句子是多余的。

Food is life; it gives us the nourishment (营养) we need to stay alive and be healthy. __小题1:__ Brian Wansink, a professor at the University of Illinois, says we also eat certain foods because they make us feel good, and remind us of happy memories. Wansink calls this kind of food comfort food. For some people, ice cream is a comfort food. For others, a bowl of noodles soup makes them feel good.

__小题2:_ Professor Wansink believes that we connect food with important times, feelings, and people in our lives. “When I was a child, my mother made a delicious soup; I loved it. __小题3:__ And it helps me feel better,” Says one of Wansink’s coworkers.

Do men and women choose different comfort foods? Wansink’s research at the University of Illinois says “ yes”. In his study, the favorite comfort food for both men and women was ice cream. After this, men usually preferred hot, savory (香的) foods like soup or noodles. __小题4:__ Men and women like to eat comfort foods when they are happy, but women eat these foods more when they are sad or worried.

__小题5:__ About 40 percent of the comfort foods in Wansink’s study were healthy main dishes or soups and vegetables. It shows, says Wansink, that a comfort food can taste good and be good for you.

Not all comfort food is junk food.

Where can we buy this sort of food?

Sweet foods are also their preference.

How does a food become comfort food?

Usually, we eat because we are hungry or need energy.

Women like sweet things such as chocolate and cookies.

Now, I often have this kind of food when I am tired or worried.

单项选择题 A1型题