How to answer a question asking me to argue "how far" I agree with a statement.

These types of questions will usually ask you a broad question, such as "There were no significant improvements in public health from 1350-1750?”
There are three key things you need to pull from this question before answering it, firstly look at the time, there is no point in discussing the introduction of the NHS as this is in the 20th century and will not gain you any marks so stick to the period given.
Secondly, you need to limit your evidence and analysis to public health, such as sewage.
Lastly, the key word here is “significant” this word is vital to pay attention to as it will allow for your analysis. You will need to use evidence to prove that there were no significant improvements and then in your second half of the essay argue that there were significant improvements, in your conclusion come to an overall judgement. When discussing a point make sure you use specific facts to back up your argument, use the PEEL method in all your paragraphs if that makes things easier:
Point: there was no significant improvement in public health in the first half of this period as local and national governments failed to execute their plans. Evidence: 1388 Parliament attempt to prevent the dumping of excrement in public bodies of water. Explain: Explain why this was unsuccessful. Link: Demonstrate why this was not a significant improvement.