W2_A2_Shapes not aligned

Hi,
I’m trying to workout the assignment and the part where we define GRADED FUNCTION: propagate. I’m really stuck and appreciate a help.
I have written the code however I get an error that says shapes (1,3) and (1,3) not aligned: 3 (dim 1) != 1 (dim 0)

This is my solution:

{moderator edit: code removed - sharing your code is not allowed}

Please don’t post your code on the forum. That isn’t allowed by the community guidelines.
I have edited your message to remove the code.

If you have incompatible shapes, maybe try it without the transposition.