→ AprilJune:謝謝，原來是我公式錯了 囧 10/19 14:56
科目：經原
問題：
Using the midpoint method, the price elasticity of demand for a goog
is computed to be approximately 0.78. Which of the following events
is consistent with a 4.68% decrease in the quantity of the good demanded?
A) an increase in the price of the good from $48.00 to $50.97
B) a 16.67 percent increase in the price of the good
C) an increase in the price of the good from $65.00 to $66.98
D) a 3.65 increase in the price of the good
我自己的想法：
P2-P1 = a
(P2+P1)/2 = b
Q2-Q1 = c
(Q1+Q2)/2 = d
Midpoint methed
(a/b) / (c/d) = 0.78
c/d = 4.68%
--> a/b = 3.65%
_______________________
A) a/b = 6%
B) a/b = 16.67%
C) a/b = 3%
D) a/b = 3.65
我不懂的地方：
所拿到的解答為 A ，請經濟高手幫忙提點一下是否哪邊的算式或觀念出了錯誤
，衷心感謝。
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作者: bartenderrr (Restart) 看板: TransEcoAcc
標題: Re: [經濟] ch5 價格彈性
時間: Sun Oct 19 00:47:57 2008
這一題其實還滿簡單的。
Ed=Q變動的百分比/P變動的百分比
0.78=4.68%/P變動的百分比
P變動的百分比=6%
所以選A
※ 引述《AprilJune (希臘藍)》之銘言：
: 科目：經原
: 問題：
: Using the midpoint method, the price elasticity of demand for a goog
: is computed to be approximately 0.78. Which of the following events
: is consistent with a 4.68% decrease in the quantity of the good demanded?
: A) an increase in the price of the good from $48.00 to $50.97
: B) a 16.67 percent increase in the price of the good
: C) an increase in the price of the good from $65.00 to $66.98
: D) a 3.65 increase in the price of the good
: 我自己的想法：
: P2-P1 = a
: (P2+P1)/2 = b
: Q2-Q1 = c
: (Q1+Q2)/2 = d
: Midpoint methed
: (a/b) / (c/d) = 0.78
: c/d = 4.68%
: --> a/b = 3.65%
: _______________________
: A) a/b = 6%
: B) a/b = 16.67%
: C) a/b = 3%
: D) a/b = 3.65
: 我不懂的地方：
: 所拿到的解答為 A ，請經濟高手幫忙提點一下是否哪邊的算式或觀念出了錯誤
: ，衷心感謝。
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 123.204.16.197