有谁可以解释吗？？

v2_vehooi

I just found that there is a 2 way to calculation the percentage change in item.

1。 For example, I found that in the share market, let say stock A, the open price of stock A is 5, the closing price is 8, so to calculate the change price in percentage should be ( ( 8-5 ) / 5 ) * 100% = 60%.


2。 But I found another calculation, let say your income increase 10000 from the base rate of 50000. so to calculate the percentage change in income, that is ( 60000 - 50000 ) / ( (60000 + 50000 ) / 2 ) = 18.2%.
But if I using the above example's calculation, that is ( ( 60000 - 50000 ) / 50000 ) ) * 100% = 20%.

很抱歉，我不懂怎样把它翻译成华语。。。

而且，我还发觉一样:

比如，股价从0.12上升到0.36
以第一的方法，the percentage change 应该是 ：　( (0.36-0.12)/0.12 ) * 100 = 200%
但以第二的方法就 　：　{ (0.36-0.12) / (　( 0.36+0.12) / 2 ) } * 100 =
                        (  0.24  /  0.24 ) * 100 = 100%

到底为什么会这样呢？？？？

flash

原帖由 v2_vehooi 于 31-3-2007 12:47 AM 发表
But I found another calculation, let say your income increase 10000 from the base rate of 50000. so to calculate the percentage change in income, that is ( 60000 - 50000 ) / ( (60000 + 50000 ) / 2 ) = 18.2%.
But if I using the above example's calculation, that is ( ( 60000 - 50000 ) / 50000 ) ) * 100% = 20%.  

请问为何要 (60000 + 50000 ) / 2 这个步骤？

jinqwem

我的疑问和楼上相同,
(5000+6000)/2 比较象是数字和MEAN 的距离, 没有用过来算PERCENTAGE的....

v2_vehooi

我也不懂啊。。。。在读financial book时看到这个formula的