TL;DR
The test for the exercise is throwing what appear to be correctish values for A, but there are 3 of them. This is causing the test to fail.
Background

I am calculating
A
as the sigmoid of the dot product ofw.T
andX
plusb
using thesigmoid(z)
function defined in Exercise 3. 
I have printed the output to the terminal to show that the values for A appear to be in line with what should be expected (sans the 3x repetition of A)
…but
 I don’t understand why the 3x repetition is occurring
The output of my failing test is below:
I appreciate any pointers that can be provided.