Hey,
I think that your assessment has good potential but your communication is letting down your ideas, research and understanding so this is what I will mostly focus on in my feedback. Although I am focusing on things to improve please also note that there are things you have done well, such as including formulas and references.
You could see a lot of improvement from addressing your use of language. Even though this isn't an English assessment, you do need to "communicate using mathematical, statistical and everyday language and conventions " fluently and at the moment there's a fair bit of room for improvement here. In particular, you need to be careful with how you use mathematical terminology like "statistics" to ensure you are using terminology correctly and making appropriate word choices.
Sometimes it comes across like you are trying to make your writing sound sophisticated through use of complex sentences and unfamiliar words but this is reducing your clarity and ability to communicate clearly and accurately. There are also a few typos / missing words / added words so you'll want to go back through and correct these. For example this issue occurs in "According to The Conversation article written by McGuigan and Salo, that although the world records have improved, it does not necessarily imply that the development of the record is ‘speeding up’ rather, the human limits in a short-term perspective must be observed and considered in this investigation" and "However, with the two outliers found at (1931, 12) and (1973, 10.8 ) may counteract these findings with the possibility of a moderate, negative correlation". This example sentence also shows another area for improvement - making sure that you build a logical argument that clearly supports your conclusions. Your conclusions and thinking makes sense but you could improve your explanations of why you have drawn them. Please also make sure you maintain consistency (e.g. in how you report your R^2 value).
You may also want to check your use of subheadings (e.g. "data collection" in "The Plan" section also includes data processing) and consistency with tense (i.e. past, present, future).
I also highly recommend you read or reread the
sample assessment information for the PSMT. In particular, I advise you to mostly focus on the high scoring sample response and the comments attached to it.
Best of luck and please let me know if you have any follow up questions!