<P style="TEXT-ALIGN: left; MARGIN: 0cm 0cm 0pt; mso-layout-grid-align: none" class=MsoNormal align=left><SPAN style="FONT-FAMILY: 'T11','sans-serif'; ; mso-bidi-font-family: T11; mso-font-kerning: 0pt" lang=EN-US>5.7 </SPAN><SPAN style="FONT-FAMILY: 'T10','sans-serif'; ; mso-bidi-font-family: T10; mso-font-kerning: 0pt" lang=EN-US>Ambrose's utility function is </SPAN><SPAN style="FONT-FAMILY: 'T9','sans-serif'; ; mso-bidi-font-family: T9; mso-font-kerning: 0pt" lang=EN-US>U</SPAN><SPAN style="FONT-FAMILY: 'T5','sans-serif'; ; mso-bidi-font-family: T5; mso-font-kerning: 0pt" lang=EN-US>(</SPAN><SPAN style="FONT-FAMILY: 'T9','sans-serif'; ; mso-bidi-font-family: T9; mso-font-kerning: 0pt" lang=EN-US>x; y</SPAN><SPAN style="FONT-FAMILY: 'T5','sans-serif'; ; mso-bidi-font-family: T5; mso-font-kerning: 0pt" lang=EN-US>) = </SPAN><SPAN style="FONT-FAMILY: 'T9','sans-serif'; ; mso-bidi-font-family: T9; mso-font-kerning: 0pt" lang=EN-US>x</SPAN><SPAN style="FONT-FAMILY: 'T5','sans-serif'; ; mso-bidi-font-family: T5; mso-font-kerning: 0pt" lang=EN-US>+ 4</SPAN><SPAN style="FONT-FAMILY: 'T9','sans-serif'; ; mso-bidi-font-family: T9; mso-font-kerning: 0pt" lang=EN-US>y</SPAN><SUP><SPAN style="FONT-FAMILY: 'T8','sans-serif'; ; mso-bidi-font-family: T8; mso-font-kerning: 0pt" lang=EN-US>1/2</SPAN></SUP><SPAN style="FONT-FAMILY: 'T10','sans-serif'; ; mso-bidi-font-family: T10; mso-font-kerning: 0pt" lang=EN-US>. The price of </SPAN><SPAN style="FONT-FAMILY: 'T9','sans-serif'; ; mso-bidi-font-family: T9; mso-font-kerning: 0pt" lang=EN-US>x </SPAN><SPAN style="FONT-FAMILY: 'T10','sans-serif'; ; mso-bidi-font-family: T10; mso-font-kerning: 0pt" lang=EN-US>is 1 and the price of </SPAN><SPAN style="FONT-FAMILY: 'T9','sans-serif'; ; mso-bidi-font-family: T9; mso-font-kerning: 0pt" lang=EN-US>y </SPAN><SPAN style="FONT-FAMILY: 'T10','sans-serif'; ; mso-bidi-font-family: T10; mso-font-kerning: 0pt" lang=EN-US>is 2. If his income rises from 100 to 150, his consumption of </SPAN><SPAN style="FONT-FAMILY: 'T9','sans-serif'; ; mso-bidi-font-family: T9; mso-font-kerning: 0pt" lang=EN-US>y </SPAN><SPAN style="FONT-FAMILY: 'T10','sans-serif'; ; mso-bidi-font-family: T10; mso-font-kerning: 0pt" lang=EN-US>increases by more than 10% but less than 50%.
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<P style="TEXT-ALIGN: left; MARGIN: 0cm 0cm 0pt; mso-layout-grid-align: none" class=MsoNormal align=left><SPAN style="FONT-FAMILY: 宋体; ; mso-bidi-font-family: T10; mso-font-kerning: 0pt; mso-ascii-font-family: T10; mso-fareast-font-family: 宋体; mso-fareast-theme-font: minor-fareast; mso-hansi-font-family: T10">答案：</SPAN><SPAN style="FONT-FAMILY: 'T12','sans-serif'; ; mso-bidi-font-family: T12; mso-font-kerning: 0pt" lang=EN-US>Topic: Choice<SPAN style="mso-tab-count: 2">            </SPAN>Difficulty: 2
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<P style="TEXT-ALIGN: left; MARGIN: 0cm 0cm 0pt; mso-layout-grid-align: none" class=MsoNormal align=left><SPAN style="FONT-FAMILY: 'T12','sans-serif'; ; mso-bidi-font-family: T12; mso-font-kerning: 0pt" lang=EN-US>% Correct Responses: 64 <SPAN style="mso-tab-count: 2">         </SPAN>Discrimination Index: 54
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<P style="TEXT-ALIGN: left; MARGIN: 0cm 0cm 0pt; mso-layout-grid-align: none" class=MsoNormal align=left><SPAN style="FONT-FAMILY: 'T12','sans-serif'; ; mso-bidi-font-family: T12; mso-font-kerning: 0pt" lang=EN-US>Correct Answer: True
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<P style="MARGIN: 0cm 0cm 0pt" class=MsoNormal><SPAN style="FONT-FAMILY: 'T10','sans-serif'; ; mso-bidi-font-family: T10; mso-font-kerning: 0pt" lang=EN-US>
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<P style="MARGIN: 0cm 0cm 0pt" class=MsoNormal><SPAN style="FONT-FAMILY: 宋体; ; mso-bidi-font-family: T10; mso-font-kerning: 0pt; mso-ascii-font-family: T10; mso-fareast-font-family: 宋体; mso-fareast-theme-font: minor-fareast; mso-hansi-font-family: T10">为什么正确啊？</SPAN><SPAN style="FONT-FAMILY: 'T10','sans-serif'; ; mso-bidi-font-family: T10; mso-font-kerning: 0pt" lang=EN-US>Y</SPAN><SPAN style="FONT-FAMILY: 宋体; ; mso-bidi-font-family: T10; mso-font-kerning: 0pt; mso-ascii-font-family: T10; mso-fareast-font-family: 宋体; mso-fareast-theme-font: minor-fareast; mso-hansi-font-family: T10">不是等于</SPAN><SPAN style="FONT-FAMILY: 'T10','sans-serif'; ; mso-bidi-font-family: T10; mso-font-kerning: 0pt" lang=EN-US>4</SPAN><SPAN style="FONT-FAMILY: 宋体; ; mso-bidi-font-family: T10; mso-font-kerning: 0pt; mso-ascii-font-family: T10; mso-fareast-font-family: 宋体; mso-fareast-theme-font: minor-fareast; mso-hansi-font-family: T10">不变吗？晕了。。。</SPAN><SPAN style="FONT-FAMILY: 'T10','sans-serif'; ; mso-bidi-font-family: T10; mso-font-kerning: 0pt" lang=EN-US>
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<P style="MARGIN: 0cm 0cm 0pt" class=MsoNormal><SPAN style="FONT-FAMILY: 宋体; ; mso-bidi-font-family: T10; mso-font-kerning: 0pt; mso-ascii-font-family: T10; mso-fareast-font-family: 宋体; mso-fareast-theme-font: minor-fareast; mso-hansi-font-family: T10">谢谢</SPAN><SPAN style="" lang=EN-US>
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