Help multiplying a vector through a matrix

[enoel2]

Hi. So say I have a 4x4 matrix in Excel occupying cells A1-D4. Then I have a 4x1 vector in A11-14. I want to multiply the matrix into the vector such that A1 is multiplied by A11*A11, A2=A2*A11*A12, A3=A3*A11*A13...B1=B1*A12*A11...D4=D4*A13*A13

If that doesn't make sense, the diagonals of the matrix are multiplied by the corresponding element in the vector twice and the (i,j) element of the matrix is multiplied by the ith and the jth element of the vector.

Can someone please tell me how to easily do this in Excel? This is pretty easy if the matrices are small, but I need to do it for like a 100x100 matrix, so I obviously can't do it manually. Any help?

Thanks a lot!

[protonLeah]

Lookup the MMULT function in help. E.g.: for a product in cells H1:H4, select the cells (H1:H4), then with the cells selected, type:

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