Matrix formula problem

[don.harvey]

I am trying to bypass the intermediate steps in the attachment. The array formula in cell Q34 works but the amendments to it by adding areference to the transpose matrix fails. I have checked my syntax. I want to have a single reference to the rrar P. I want to calculate the result into a 7x1 matrix in S34 that should be the same as Q34

[shg]

If I understand your question, change the formula in Q34 to

=MMULT( MMULT( ( MINVERSE(MMULT(TRANSPOSE(P), P) ) ),TRANSPOSE(P) ), $Q$8:$Q$16)