Here's the exam paper which provides the scenario that lead me to this question. (Question 1 is what I'm focusing on here.) http://qualifications.pearson.com/content/dam/pdf/International%20Advanced%20Level/Physics/2013/Exam%20materials/WPH06_01_que_20160201.pdf
For starters, am I crazy? Or is there a difference between a +/- uncertainty and an uncertainty that is not +/-. Part (b)(iii) shows no discrimination. It states 0.6% or 1.1% as the uncertainty.
Moreover, here is why that's important in the part that really confuses me: part (d). How would I calculate the maximum and minimum values possible from the uncertainty provided? The value that is talked about is 1.16, and it has a 4% uncertainty. I used 1.16(1.04) in order to calculate the maximum value. Is this right? I would guess not based upon the fact that this the 4% uncertainty isn't +/-. If yes, then based upon a random phrase that I've seen somewhere in a stats book, 'the confidence interval moves around the mean', if this weird 'confidence interval' concept applies here then I may be right, but can someone please explain?
Finally, back to part (b)(iii), if the answer for part (d) is indeed 1.16(1.04), then would the minimum value for the volume of the rubber bung be 1.52(1-0.0057) or 1.52(1-0.0104) because I have to multiply the 0.57% uncertainty by 2 (since its +/-)?
Honestly thanks to everyone on this site for their continuous help and very valuable time. Someone please help me. I have a final exam coming up and uncertainties are stupidely difficult because of the many discrepancies and what seems to be a requirement of a strong background of knowledge of statistics, which I haven't time to develop. I understand high rep users are busy, but someone please help me.