STAR Technique? (for Economics/Finance/Accountancy roles)Watch
The second one, for an entry level graduate role, almost certainly has to be about how you managed the most hectic period you had at Uni. It's just asking about your organisation and how you manage high tempo work and deliver to a deadline. STAR would work here
The third one is asking about a time you influenced people, could be something as simple as convincing a sports team to change league, or enter a competition. Again, its amenable to STAR.
So the first question is not amenable to the STAR format. You have to take some knowledge you have (data analysis using economic tools) and demonstrate how you would present it to a specific category of person (senior stakeholders) to achieve/influence some specific outcome (future policy).
There's no good just looking at your life randomly for examples. What you have to start with is the skills employers want to know about, and the cluse for that are in the job advert/recruitment website. So the job that asked those questions clearly wanted 3 things - someone who can deliver data analysis to senior people, someone who can organise their life to juggle multiple priorities and still meet deadlines and someone who works well in a team and can perhaps influence people outside the team. Read enough job adverts and you will see a regular pattern of skills and you need to prepare examples for each that you can draw on in interview.
Threeportdrift has covered the questions bit in pretty much the same way I intended to. Don't be afraid to apply for jobs, just make sure you analyze the advert and understand what it's telling and asking you
The skills and attitudes that got you through your degree to a successful conclusion are the ones you now need to show to an employer as being the reason you will be a cracking employee
Reverse the question - what if I say - "you've never had to organise yourself to meet multiple deadlines in your life". If you can't defend that statement, you are punting for jobs that are beyond you - if you can defend that statement - then there is your evidence! You might even find better examples that just Uni work, which is pretty basic.