This task was difficult for all the wrong reasons. The other four were quite well put together, as they provide just enough guidance for you to figure out what you need to do but not to give away the answer. The issue with this particular task is that the instructions can be interpreted in many different ways, without any of them being “wrong”, which leads to many of us doing this in a way that makes sense but results in the wrong answer. There should be a little more clarity (without giving anything away) and the test function at the end should be fixed, because that makes no sense. Overall, I’m very pleased with all 5 projects and they set you up quite well for doing more projects on your own.
For the other task, you just need to build a basic network with tensor flow rather than doing a linear model (I assume you tried this based on the titanic dataset part of the accompanying lectures). They give you a hint in the imports cell
from tensorflow.keras import layers
and the lack of importing of the linear classifier, which suggests that you need to build a neural network with some layers. However, this is probably more suited for a separate post topic or direct messaging. Hope this helps.