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Math HL Paper 3, Probability and Statistics


Negotiation

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Guest MysteryDude

Horrible. I was not prepared for it at all, and I think it might be my teacher's fault. We studied normal distribution and hypothesis testing a lot, but spent maybe 15 minutes talking about geometric distribution. He forgot to teach us PGFs during class and did that in in the weekend before the exam, so I was really not prepared for that.

Overall, the exam was really different from what I've seen in the past papers. The regression lines question was alright, although no one in my class got the same answer for the angle so I'm pretty sure mine is wrong. Screwed up 3 & 4, but I at least attempted them, so I pray for partial marks. I hope I got at least half of it right -____- I really need a 5 in this class.

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Guest MysteryDude

The regression lines question was alright, although no one in my class got the same answer for the angle so I'm pretty sure mine is wrong.

I got 7 degrees for this. What did you get?

... 81 :D

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Guest MysteryDude

Yep! But I didn't have enough time to compete the paper, so I rushed through this question and screwed up somewhere. But I think grade boundaries should be really low this year. New syllabus, hard exam - we should be fine.

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About that angle question, I still have the values on my GDC so I just checked my result. I seemed to have got 38.4°, I took the arctan of the two gradients (which I copied down from my GDC) and found the difference between them. Oddly enough MysteryDude, adding them together gives 82.9°...

I said this on the other thread too, but I was also screwed over by the PGF/CDF question.

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About that angle question, I still have the values on my GDC so I just checked my result. I seemed to have got 38.4°, I took the arctan of the two gradients (which I copied down from my GDC) and found the difference between them. Oddly enough MysteryDude, adding them together gives 82.9°...

I said this on the other thread too, but I was also screwed over by the PGF/CDF question.

Yeah the end of question 2, i still don't quite understand how that question fits into a stats paper, i just treated both the lines of best fit as vectors, and figured out the angle that way, and got 38.4. The thing i was most worried about for the paper was the PGF question, cause its new on the syllabus, but tbh question 4 wasn't too bad at all. lucky days. As if there were no confidence intervals, and pretty much no hypothesis testing, only a bit of p-value in question 2. :/

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About that angle question, I still have the values on my GDC so I just checked my result. I seemed to have got 38.4°, I took the arctan of the two gradients (which I copied down from my GDC) and found the difference between them. Oddly enough MysteryDude, adding them together gives 82.9°...

I said this on the other thread too, but I was also screwed over by the PGF/CDF question.

According to my calculations, these are the gradients and the angle between them is 0.1236 radians which equates to ≈7 degrees.

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