Weighted average with specific conditions

[lfmemp]

Hi there,

I need to calculate a weighted average based on specific conditions.
For example in the tables below, I have the data in sheet 1.
What I am looking for, is to get the weighted average of the 'rate' based on the 'tons' only for the same date and the same line. So on the 23/07/2012 anf for the line J1, I should get the weighted average of the rate based on the tons that date.


see Sheet 1

The output I need is in the table below, sheet 2. My output is the 'weighted average of rate' cell and in the 'formula' cell I just show how it should be calculated

see Sheet 2

Can somebody help me what formula to use to calculate the 'weighted aver of rate'?

Thank you

Table 1.pngSheet 2.png