题干

某校为了解2014年八年级学生课外书籍借阅情况,从中随机抽取了40名学生课外书籍借阅情况,将统计结果列出如下的表格,并绘制成如图所示的扇形统计图,其中科普类册数占这40名学生借阅总册数的40%.

类别

科普类

教辅类

文艺类

其他

册数(本)

128

80

m

48

(1)求表格中字母m的值及扇形统计图中“教辅类”所对应的圆心角a的度数;

(2)该校2014年八年级有500名学生,请你估计该年级学生共借阅教辅类书籍约多少本?


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答案(点此获取答案解析)

解:(1)观察扇形统计图知:科普类有128册,占40%,
∴借阅总册数为128÷40%=320本,
∴m=320﹣128﹣80﹣48=64;
教辅类的圆心角为:360°×80300
=90°;
(2)设全校500名学生借阅教辅类书籍x本,

同类题3

阅读理解Answer the questions

    You are invited to a large party. Loud music is playing, and lots of people are dancing. Do you dance or talk to as many people as you can call all night? Later, you cannot fall asleep—you want more conversation! Or do you prefer a quieter corner? Or perhaps you cannot wait to go home early and relax by yourself.

    Which of these people sound most like you? Person A, who tries to talk to everyone and stays late? Or Person B, who prefers to keep quiet and leaves early?

    If you said Person A, you are probably more extroverted(性格外向的). If you said Person B, you are probably more introverted(内向的). Or perhaps you are Person C and fall somewhere in the middle. Introverted and extroverted people are two commonly used words to describe a person's personality. And they are also commonly misused and misunderstood.

    Introverts may be thought as quiet, shy and timid. Extroverts may be thought as bold, confident, loud and full of energy. Introverted and extroverted people may fit those descriptions. But these same descriptions do not define(下定义)introversion and extroversion properly.

    Introverts and extroverts use their brains differently, and they get their energy differently. Introversion is the state of being mostly concerned with one's own mental life. Extroversion is the opposite. Extroversion is the state of being mostly concerned with what is outside oneself.

    People who consider themselves introverts may say they “need to be alone to charge their batteries”. However, introverts may still live being social and going to parties. But such activities require time to prepare.

    Extroverts may say, “I don't need ‘alone time', I feel more relaxed being around other people.” Even so, extroverts can still feel unsure or not confident among other people.

    So where do you fall on the introversion/ extroversion chart?