Returning a value determined by multiple criteria on seperate Worksheet using Sumproduct

Hello All,

I am hoping someone can help me in here please.

I have a spreadsheet which needs to reference data in another tab of the worksheet and return a value (all values in both sheets are formatted as 2 decimal place numbers). To grab the correct value 3 different fields/criteria from Sheet1 must match 3 fields in a table from Sheet2 and then the value from a 4th field needs to be returned to a cell on Sheet1(data being taken from sheet2).

I can get this to work if both sets of data are on the same sheet but this isn't what the company is after and is a messy solution.

When on the same sheet this formula works perfectly =SUMPRODUCT(--(G:G=A2),--(H:H=B2),--(I:I=C2),J:J)

I have gotten the formula to this stage where it is looking at a different sheet but it gives a 0 value (which is incorrect) =SUMPRODUCT(--('Sheet2 Delta Array'!A:A=A2),--('Sheet2 Delta Array'!B:B=B2),--(Sheet2!C:C=C2),('Sheet2 Delta Array'!D:D))

I think from what I have read the Indirect function needs to be incorporated but I am not knowledgeable enough and have not been able to do this.

I would really appreciate any advice, thanks.

Thanks or the pickup, sorry I was retyping the formula and changed sheet names due to a spelling mistake. This is not the problem however as the formula is actually
=SUMPRODUCT(--('Weigthted Delta Array'!A:A=A2),--('Weigthted Delta Array'!B:B=B2),--('Weigthted Delta Array'!C:C=C2),('Weigthted Delta Array'!D:D))

please excuse the spelling.