Typo in the video "Forward prop in a single layer": w2_1 must be 3 element vector

Course Q&A Machine Learning Specialization Advanced Learning Algorithms
1

In section “Neural network implementation in Python”, in the 1st video “Forward prop in a single layer” at 4:27 there is a typo (repeated in the Practice quiz):

w2_1 = np.array( [-7, 8] ) must be a 1D vector with 3 elements (not 2 as shown).

The 2 element vector can not legally dot-product with a 1D vector with 3 elements:

a1 = np.array( [a1_1, a1_2, a1_3] )

2

Thank you very much @Robert_Ascan. We have reported this typo, together with the one in the quiz, to the course team.

Raymond