電漿電視的弧彈性絕對值大於1，算需求量 - 經濟

來源: 93學年度技術學院專業科目(一) 管理類(二)管理類(四) 經濟學

科目:經濟學

問題:

假設某型電漿電視為正常財，消費者對其需求的弧彈性之絕對值大於1，當價格由每台20
萬元降為15萬元時，需求量會如何變動?

(A)增加，幅度小於14%
(B)減少，幅度大於28%
(C)增加，幅度大於28%
(D)減少，幅度小於14%
答案是:C

我的想法:令P1=200,000 P2=150,000 原本的需求量Q1 後來的需求量Q2

套入弧彈性的公式， ｜(Q2-Q1/Q2+Q1) 整個除以2｜
_____________________________ > 1
｜(P2-P1)/(P2+P1) 整個除以2｜

= = = = = = = = = = = = = = = = = = = = = = = = == ==

｜(Q2-Q1/Q2+Q1)｜ ｜(Q2-Q1/Q2+Q1)｜
____________________ = __________________ >1

｜-50,000/350,000｜ 1/7

= = = = = = = = = = = = = = = = = == === = = = = = = = = = = = = = =
｜(Q2-Q1/Q2+Q1)｜>7 所以 (Q2-Q1/Q2+Q1)>7 或 (Q2-Q1/Q2+Q1)<-7
= = = = = = = = = = = = = == = = = = = = = = = = = = = = = = = = = =
算出來Q2 >4/3 Q1 但怎麼會是大於28%呢？
高手可以幫我解惑嗎？謝謝。

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