Calculation of Weightage Average

[C_ChetanChaudhari]

Hi,

I've to Calculate weightage on the basis of different keys. So, I wrote the expression for it as mentioned below but it's not working.

Aggr(Sum(Book Value)/Sum(total Book Value),Key1)

Below are the inputs.

KEY1	KEY2	BookValue	Weigtage1 (On the basis Of Key 1)	Weigtage2 (On the basis Of Key 2)
A	Z	100	0.333333333	1
A	Y	200	0.666666667	1
B	X	300	1	0.25
C	X	400	1	0.333333333
D	X	500	1	0.416666667

Could anyone help me. How I can achieve it ?

Thanks in advance.

Chetan C