题干

设某大学的女生体重y(单位:kg)与身高x(单位:cm)具有线性相关关系,根据一组样本数据(xi,yi)(i=1,2,…,n),用最小二乘法建立的回归方程为y=0.85x-85.71,则下列结论中不正确的是(      ) 

A:y与x具有正的线性相关关系

B:回归直线过样本点的中心(x-y-

C:若该大学某女生身高增加1cm,则其体重约增加0.85kg

D:若该大学某女生身高为170cm,则可断定其体重比为58.79kg

上一题 下一题 0.0难度 选择题 更新时间:2015-12-11 08:10:00

答案(点此获取答案解析)

D

同类题2

阅读理解

    Henry had been a journalist for many years. He had worked on many international newspapers and magazines and traveled all over the world.

    Henry had witnessed wars and natural disasters such as floods, earthquakes and erupting volcanos(火山爆发). He had reported on serious accidents such as major fires and airline crashes. He had seen every kind of terrible crime and strange event there was. He had met and written about some of the most unusual people in the world. In fact, there wasn't much that Henry had not seen or done.

    Now he was retired from journalism. He owned a very expensive restaurant and spent his days talking to his wealthy and important customers. He liked to say that nothing surprised him.

    One day he was sitting at the bar in his restaurant when a big gorilla walked in and asked for a table. Henry showed no surprise. He took the gorilla to a table and handed him a menu. He treated him politely and pretended there was nothing at all strange about having a gorilla in his restaurant.

    The gorilla looked through the menu and ordered a salad. Henry served the gorilla his salad personally, knowing that his waiters and waitresses would be too frightened. At last the gorilla finished his salad and asked for the bill. Henry wrote out the bill and handed it to the big animal. The gorilla studied it, shook his head sadly, then gave Henry fifty dollars.

    "Thank you", Henry said, and then to make conversation he added, "We don't get many gorillas in this restaurant."

    "At fifty dollars for a salad," the gorilla said, "I'm not surprised."