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xiaobaiybz · 2020年02月18日

问一道题：NO.PZ2015120204000044 [ CFA II ]

  1. CFA II
  2. Quantitative

问题如下：

After applying data transformations, Steele scales the financial data using normalization. She notes that over the full sample dataset, the “Interest Expense” variable ranges from a minimum of 0.2 and a maximum of 12.2, with a mean of 1.1 and a standard deviation of 0.4.

Exhibit 1 Sample of Raw Structured Data Before Cleansing


Based on Exhibit 1, for the firm with ID #3, Steele should compute the scaled value for the “Interest Expense” variable as:

选项：

A.

0.008.

B.

0.083.

C.

0.250.

解释：

B is correct. Steele uses normalization to scale the financial data. Normalization is the process of rescaling numeric variables in the range of [0, 1]. To normalize variable X, the minimum value (Xmin) is subtracted from each observation
(Xi), and then this value is divided by the difference between the maximum and minimum values of X (Xmax – Xmin):
The firm with ID #3 has an interest expense of 1.2. So, its normalized value is calculated as:

Xi(normalized) =(1.2-0.2)/(12.2-0.2)=0.083

是因为题干中没说是正态分布，所以不用mean和标准差求解吗？

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1 个答案

Marina_0122 · 2020年02月19日

这个题目对应Data wrangling: scaling那个知识点。 Normalization有个公式的。

艾米丽 · 2021年01月23日

老师，我觉得你没有直接回答他的问题，就是想知道同样给了方差，平均值还有最大小值得时候，我们怎么选择是normalization 还是standardization？

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NO.PZ2015120204000044 0.083. 0.250. B is correct. Steele uses normalization to scale the financitNormalization is the process of rescaling numeric variables in the range of [0, 1]. To normalize variable X, the minimum value (Xmin) is subtractefrom eaobservation (Xi), anthen this value is vithe fferenbetween the maximum anminimum values of X (Xm– Xmin): The firm with I#3 hinterest expense of 1.2. So, its normalizevalue is calculateas: Xi(normalize =(1.2-0.2)/(12.2-0.2)=0.083 解答说要用normalization来做rescaling，那么stanrzation应该什么时候用呢？

2021-08-23 07:51 1 · 回答

NO.PZ2015120204000044 这个知识点没有找到，请问一下在讲义的哪个位置

2021-03-06 10:11 1 · 回答

0.083. 0.250. B is correct. Steele uses normalization to scale the financitNormalization is the process of rescaling numeric variables in the range of [0, 1]. To normalize variable X, the minimum value (Xmin) is subtractefrom eaobservation (Xi), anthen this value is vithe fferenbetween the maximum anminimum values of X (Xm– Xmin): The firm with I#3 hinterest expense of 1.2. So, its normalizevalue is calculateas: Xi(normalize =(1.2-0.2)/(12.2-0.2)=0.083 请问这道题涉及的知识点是？

2020-11-07 21:28 1 · 回答

0.083. 0.250. B is correct. Steele uses normalization to scale the financitNormalization is the process of rescaling numeric variables in the range of [0, 1]. To normalize variable X, the minimum value (Xmin) is subtractefrom eaobservation (Xi), anthen this value is vithe fferenbetween the maximum anminimum values of X (Xm– Xmin): The firm with I#3 hinterest expense of 1.2. So, its normalizevalue is calculateas: Xi(normalize =(1.2-0.2)/(12.2-0.2)=0.083 为什么不是（1.2-1.1）/0.4=0.25？

2020-03-01 14:06 2 · 回答