假设100个数据的平均值为82.31，其中有10个数据又分别发生了如下_爱下问搜题

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问题单项选择题

假设100个数据的平均值为82.31，其中有10个数据又分别发生了如下增减变化：+3.52，+2.87，-4.13，+5.34，-2.87，+2.50，-3.52，+4.23，-5.04，+0.10，则新的平均值变为______。

A．82.34
B．82.28
C．82.61
D．85.31

答案

参考答案：A

解析：本题描述了一种动态变化情况下的平均值计算问题。已知100个数的平均值为82.31，大部分数据没有变动，只有10个数据有变动，平均值当然也会有变动。其实，只要计算出总的增减值，即将这些增减的值求和得到总的增减值；将这个增减值的和除以数据的总数，就会得到平均的增减值。和原来的平均值相加后就是变化后的平均值。
在对题中给出的各数据增减值求和时，也要讲究计算方法。例如，第1个数+3.52与后面的-3.52就抵消了，这两个数就可以划去；第2个数+2.87与后面的-2.87也抵消了；第3个数-4.13与后面的数+4.23相抵后剩余+0.10；第4个数+5.34与后面的-5.04相抵后剩余+0.30；再同剩余的几个数相加就得到了3.00的结果。因此，100个数(注意，应按100个数计算，而不是10个数)的总和将增加3.00，平均值将增加0.03结果就是82.34。

单项选择题 A3/A4型题

患者男性，38岁。吸烟15年，每天30支左右，冷库工作8年。近来，右小腿持续性剧烈疼痛，不能行走，夜间加重，到医院就诊，体检：右小腿皮肤苍白，肌萎缩，足背动脉搏动消失。

目前该患者的病变属于哪一分期（）。

A.Ⅰ期

B.Ⅱ期

C.Ⅲ期

D.Ⅳ期

E.晚期

完形填空

"Just sign here, sir," the deliveryman said as he handed Oscar Reyna a package.
The package consisted of a long, narrow box 21 wrapped in brown paper. 22 the box, Oscar saw an umbrella inside — a very old one with a beautifully carved wooden handle. 23 he had not seen it in more than 20 years, he recognized it 24 .
Oscar was 16 when he first saw the 25 umbrella. He had gone to a concert with his grandparents. As they were leaving, h noticed an umbrella on an empty seat, impressed by its 26 , Oscar felt a strong desire to find its 27 .
Oscar 28 the manager to look in the record of advance ticket sales. Just as he thought, a name matched the seat 29 Oscar had found the umbrella. The name was Mrs. Katie O'Brien.
Oscar talked his grandparents into going by Mrs. O'Brien's 30 on their way home. He rang the bell, the door opened, and an elderly woman appeared. "May I 31 you?" she asked.
"I'd like to return it if it's yours," Oscar said, 32 the umbrella as if presenting a 33 that had long been wished for.
"Why, yes! It's mine," replied Mrs. O'Brien with a 34 smile and shining eyes. "It was given to me by my father years ago. Thank you so much for returning it. May I offer you a reward for your __35_ ?"
"No, ma'am," he said, "My grandmother says that a good deed is its own reward. "
"Well, that's 36 what my father used to say. What is your name, young man?"
Years later Oscar was staring at the finely carved handle of the umbrella as he remembered Mrs. O'Brien. It was in perfect condition, considering how 37 it was. Why had it arrived here today?
As if 38 , a note fell from the paper. It reads: Mrs. O'Brien wanted to 39 this umbrella as a present for a kind, 40. gesture long ago.

C．immediately

D．neighborhood

B．turning out

D．holding out

D．determination

A．in contrast

C．in exchange

B．significant

D．sympathetic