请问c选项是怎么看出来要求的是fisher index？没理解c说的意思
问题如下图：
选项：
A. 
B. 
C. 
解释：
NO.PZ2017100901000024问题如下 The following presents selectecommoty prita for July–August 2015:Given the consumption basket anprices presente whitype of priinx will result in the highest calculateinflation rate over a two-month time perioA.One thuses a current consumption basketB.One thuses a constant consumption basketC.One reflecting substitutions ma consumers over time B is correct.The inflation rate calculateusing a constant consumption basket (the Laspeyres inx) is 10%, rivefollows: July 2015 consumption basket = (18 × €1) + (6 × €2) = €30 August 2015 consumption basket = (18 × €1) + (6 × €2.5) = €33 Value of the Laspeyres inx (IL) = (€33/€30) × 100 = €110 Inflation rate = (110/100) – 1 = 0.10 = 10%The inflation rate calculateusing a current consumption basket (the Paasche inx) is 8%, rivefollows: July 2015 consumption basket = (17 × €1) + (4 × €2) = €25 August 2015 consumption basket = (17 × €1) + (4 × €2.5) = €27 Value of the Paasche inx (IP) = (€27/€25) × 100 = €108 Inflation rate = (108/100) – 1 = 0.08 = 8%The inflation rate calculate\"chaining\" the monthly prices of consumption baskets they change over time (the Fisher inx) is rivefollows: Value of the Fisher inx = (Ip*IL)^0.5 Value of the Fisher Inx =(110*108)^0.5=108.99 Inflation rate = (108.99/100) – 1 = 0.0899 = 8.99%考点拉式指数法解析在拉氏指数法下，应该是用基期的消费篮子:7月物价水平(18 × € 1) + (6 × € 2) = € 30 8月物价水平(18 × € 1) + (6 × € 2.5) = € 33通胀指数Inflation rate=(33/30)-1=10%在沠许指数法下,应该是用当期的消费篮子7月的物价水平(17 × € 1) + (4 × € 2) = € 25 8月的物价水平(17 × € 1) + (4 × € 2.5) = € 27 通胀指数(27/25)-1=8%费雪指数(110*108)^0.5= € 108.99 通胀指数(108.99/100) – 1 = 0.0899 = 8.99%由此可见B正确。 什么是constant ，老师在课程哪里有讲过，还有这道题的思路是什么
NO.PZ2017100901000024 问题如下 The following presents selectecommoty prita for July–August 2015:Given the consumption basket anprices presente whitype of priinx will result in the highest calculateinflation rate over a two-month time perio A.One thuses a current consumption basket B.One thuses a constant consumption basket C.One reflecting substitutions ma consumers over time B is correct.The inflation rate calculateusing a constant consumption basket (the Laspeyres inx) is 10%, rivefollows: July 2015 consumption basket = (18 × €1) + (6 × €2) = €30 August 2015 consumption basket = (18 × €1) + (6 × €2.5) = €33 Value of the Laspeyres inx (IL) = (€33/€30) × 100 = €110 Inflation rate = (110/100) – 1 = 0.10 = 10%The inflation rate calculateusing a current consumption basket (the Paasche inx) is 8%, rivefollows: July 2015 consumption basket = (17 × €1) + (4 × €2) = €25 August 2015 consumption basket = (17 × €1) + (4 × €2.5) = €27 Value of the Paasche inx (IP) = (€27/€25) × 100 = €108 Inflation rate = (108/100) – 1 = 0.08 = 8%The inflation rate calculate\"chaining\" the monthly prices of consumption baskets they change over time (the Fisher inx) is rivefollows: Value of the Fisher inx = (Ip*IL)^0.5 Value of the Fisher Inx =(110*108)^0.5=108.99 Inflation rate = (108.99/100) – 1 = 0.0899 = 8.99%考点拉式指数法解析在拉氏指数法下，应该是用基期的消费篮子:7月物价水平(18 × € 1) + (6 × € 2) = € 30 8月物价水平(18 × € 1) + (6 × € 2.5) = € 33通胀指数Inflation rate=(33/30)-1=10%在沠许指数法下,应该是用当期的消费篮子7月的物价水平(17 × € 1) + (4 × € 2) = € 25 8月的物价水平(17 × € 1) + (4 × € 2.5) = € 27 通胀指数(27/25)-1=8%费雪指数(110*108)^0.5= € 108.99 通胀指数(108.99/100) – 1 = 0.0899 = 8.99%由此可见B正确。 需要算这么多吗，我直接算了L式和P式就得出来了结论。对吗
NO.PZ2017100901000024问题如下 The following presents selectecommoty prita for July–August 2015:Given the consumption basket anprices presente whitype of priinx will result in the highest calculateinflation rate over a two-month time perioA.One thuses a current consumption basketB.One thuses a constant consumption basketC.One reflecting substitutions ma consumers over time B is correct.The inflation rate calculateusing a constant consumption basket (the Laspeyres inx) is 10%, rivefollows: July 2015 consumption basket = (18 × €1) + (6 × €2) = €30 August 2015 consumption basket = (18 × €1) + (6 × €2.5) = €33 Value of the Laspeyres inx (IL) = (€33/€30) × 100 = €110 Inflation rate = (110/100) – 1 = 0.10 = 10%The inflation rate calculateusing a current consumption basket (the Paasche inx) is 8%, rivefollows: July 2015 consumption basket = (17 × €1) + (4 × €2) = €25 August 2015 consumption basket = (17 × €1) + (4 × €2.5) = €27 Value of the Paasche inx (IP) = (€27/€25) × 100 = €108 Inflation rate = (108/100) – 1 = 0.08 = 8%The inflation rate calculate\"chaining\" the monthly prices of consumption baskets they change over time (the Fisher inx) is rivefollows: Value of the Fisher inx = (Ip*IL)^0.5 Value of the Fisher Inx =(110*108)^0.5=108.99 Inflation rate = (108.99/100) – 1 = 0.0899 = 8.99%考点拉式指数法解析在拉氏指数法下，应该是用基期的消费篮子:7月物价水平(18 × € 1) + (6 × € 2) = € 30 8月物价水平(18 × € 1) + (6 × € 2.5) = € 33通胀指数Inflation rate=(33/30)-1=10%在沠许指数法下,应该是用当期的消费篮子7月的物价水平(17 × € 1) + (4 × € 2) = € 25 8月的物价水平(17 × € 1) + (4 × € 2.5) = € 27 通胀指数(27/25)-1=8%费雪指数(110*108)^0.5= € 108.99 通胀指数(108.99/100) – 1 = 0.0899 = 8.99%由此可见B正确。 C无法想到用费雪指数 可以下跟substitution的关系吗
NO.PZ2017100901000024问题如下 The following presents selectecommoty prita for July–August 2015:Given the consumption basket anprices presente whitype of priinx will result in the highest calculateinflation rate over a two-month time perioA.One thuses a current consumption basketB.One thuses a constant consumption basketC.One reflecting substitutions ma consumers over time B is correct.The inflation rate calculateusing a constant consumption basket (the Laspeyres inx) is 10%, rivefollows: July 2015 consumption basket = (18 × €1) + (6 × €2) = €30 August 2015 consumption basket = (18 × €1) + (6 × €2.5) = €33 Value of the Laspeyres inx (IL) = (€33/€30) × 100 = €110 Inflation rate = (110/100) – 1 = 0.10 = 10%The inflation rate calculateusing a current consumption basket (the Paasche inx) is 8%, rivefollows: July 2015 consumption basket = (17 × €1) + (4 × €2) = €25 August 2015 consumption basket = (17 × €1) + (4 × €2.5) = €27 Value of the Paasche inx (IP) = (€27/€25) × 100 = €108 Inflation rate = (108/100) – 1 = 0.08 = 8%The inflation rate calculate\"chaining\" the monthly prices of consumption baskets they change over time (the Fisher inx) is rivefollows: Value of the Fisher inx = (Ip*IL)^0.5 Value of the Fisher Inx =(110*108)^0.5=108.99 Inflation rate = (108.99/100) – 1 = 0.0899 = 8.99%考点拉式指数法解析在拉氏指数法下，应该是用基期的消费篮子:7月物价水平(18 × € 1) + (6 × € 2) = € 30 8月物价水平(18 × € 1) + (6 × € 2.5) = € 33通胀指数Inflation rate=(33/30)-1=10%在沠许指数法下,应该是用当期的消费篮子7月的物价水平(17 × € 1) + (4 × € 2) = € 25 8月的物价水平(17 × € 1) + (4 × € 2.5) = € 27 通胀指数(27/25)-1=8%费雪指数(110*108)^0.5= € 108.99 通胀指数(108.99/100) – 1 = 0.0899 = 8.99%由此可见B正确。 B，constant consumtion就是当期消费篮子？
NO.PZ2017100901000024 问题如下 The following presents selectecommoty prita for July–August 2015:Given the consumption basket anprices presente whitype of priinx will result in the highest calculateinflation rate over a two-month time perio A.One thuses a current consumption basket B.One thuses a constant consumption basket C.One reflecting substitutions ma consumers over time B is correct.The inflation rate calculateusing a constant consumption basket (the Laspeyres inx) is 10%, rivefollows: July 2015 consumption basket = (18 × €1) + (6 × €2) = €30 August 2015 consumption basket = (18 × €1) + (6 × €2.5) = €33 Value of the Laspeyres inx (IL) = (€33/€30) × 100 = €110 Inflation rate = (110/100) – 1 = 0.10 = 10%The inflation rate calculateusing a current consumption basket (the Paasche inx) is 8%, rivefollows: July 2015 consumption basket = (17 × €1) + (4 × €2) = €25 August 2015 consumption basket = (17 × €1) + (4 × €2.5) = €27 Value of the Paasche inx (IP) = (€27/€25) × 100 = €108 Inflation rate = (108/100) – 1 = 0.08 = 8%The inflation rate calculate\"chaining\" the monthly prices of consumption baskets they change over time (the Fisher inx) is rivefollows: Value of the Fisher inx = (Ip*IL)^0.5 Value of the Fisher Inx =(110*108)^0.5=108.99 Inflation rate = (108.99/100) – 1 = 0.0899 = 8.99%考点拉式指数法解析在拉氏指数法下，应该是用基期的消费篮子:7月物价水平(18 × € 1) + (6 × € 2) = € 30 8月物价水平(18 × € 1) + (6 × € 2.5) = € 33通胀指数Inflation rate=(33/30)-1=10%在沠许指数法下,应该是用当期的消费篮子7月的物价水平(17 × € 1) + (4 × € 2) = € 25 8月的物价水平(17 × € 1) + (4 × € 2.5) = € 27 通胀指数(27/25)-1=8%费雪指数(110*108)^0.5= € 108.99 通胀指数(108.99/100) – 1 = 0.0899 = 8.99%由此可见B正确。 老师好，请问本题为什么不直接算CPI，而是分别算两个月的物价水平？CPI和inflation rate之间是什么关系呢？还有本题为什么要计算费雪指数，感觉和费雪指数没有关系啊？谢谢
