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Probabilities & Statistics 1 - OCR (not MEI) - jan 25th 2012 discussion

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Reply 140
Avatar for matty b
matty b
Original post by tooambitious
yup


I only put one (don't really know why), but was it 2 marks? If so, would I get a mark anyway for (3.5 , 6)?
Reply 141
Avatar for extons
extons
10
Original post by matty b
I only put one (don't really know why), but was it 2 marks? If so, would I get a mark anyway for (3.5 , 6)?


yes :smile:
Original post by matty b
I only put one (don't really know why), but was it 2 marks? If so, would I get a mark anyway for (3.5 , 6)?


definitely, lol i did the same thing when explaining the binmial graph, d'oh :tongue:
Well I completed screwed up the last 2 questions, and that was 20 marks.

So I'm definitely re-doing this ****ty bugger of an exam.

I'm really scared though, how much do Unis care about re-doing our exams in the summer?

Apparently it can greatly hinder your application :frown:
Reply 144
Avatar for Tukazoar
Tukazoar
Original post by planetearth
Well I completed screwed up the last 2 questions, and that was 20 marks.

So I'm definitely re-doing this ****ty bugger of an exam.

I'm really scared though, how much do Unis care about re-doing our exams in the summer?

Apparently it can greatly hinder your application :frown:


Most don't really mind, some see it as you determined to do better. Depends what you're applying for tho. I.e. if it's competitive. E.g. some will take the student with the good grades already rather than someone with bad ones and who plans to retake.
Original post by planetearth
Well I completed screwed up the last 2 questions, and that was 20 marks.

So I'm definitely re-doing this ****ty bugger of an exam.

I'm really scared though, how much do Unis care about re-doing our exams in the summer?

Apparently it can greatly hinder your application :frown:


to be completely honest it would be quite difficult for them t realise it was a retake, because on your UCAS it wuld just say summer 2013, and lots of people do s1 then anyway
Reply 146
Avatar for Molly/21
Molly/21
Original post by planetearth
Well I completed screwed up the last 2 questions, and that was 20 marks.

So I'm definitely re-doing this ****ty bugger of an exam.

I'm really scared though, how much do Unis care about re-doing our exams in the summer?

Apparently it can greatly hinder your application :frown:


Will probably still get a decent grade anyway as i go to a grammar school and nearlly everyone struggled with the last two questions. Even those who do Further Maths...
Reply 147
Avatar for linnet18
linnet18
Anyone got a list of questions or the paper? I'll do a full mark scheme.
Reply 148
Avatar for extons
extons
10
Original post by Molly/21
Will probably still get a decent grade anyway as i go to a grammar school and nearlly everyone struggled with the last two questions. Even those who do Further Maths...


Just like me :ashamed:

Never mind - life goes on!!
I guess I'm kinda the opposite to everyone here, I actually thought the last question was fine, can't remember what the 8th one was though, can anyone remind me?
But I couldn't understand 3(ii) at all. I had absolutely no idea what it was on about! It was the Bin(13,0.12) and then 2 independent variables being found and work out the probability that exactly one had the value two. Can someone explain to me what they were asking?
Reply 150
Avatar for extons
extons
10
Original post by 22AcaciaAvenue
I guess I'm kinda the opposite to everyone here, I actually thought the last question was fine, can't remember what the 8th one was though, can anyone remind me?
But I couldn't understand 3(ii) at all. I had absolutely no idea what it was on about! It was the Bin(13,0.12) and then 2 independent variables being found and work out the probability that exactly one had the value two. Can someone explain to me what they were asking?


I think you had to use the value of P(X=2), after finding it, then making another binomial 'parameter'. So it then became Y~B (2, (P(X=2))). Then you calculated:

2C1 x (p(x=2)) x (1-p).

That's what I did anyway. May be totally wrong!

Edit::::: So final answer, I got was...0.399. Think I've seen that around earlier in the thread.
(edited 12 years ago)
Original post by c_subs
where did it say in the qu. that n = 10? nd wat do u mean by C.D


I'm gutted about this :frown: I've always been taught that they will specify a distribution for it to be binomial! I definitely toyed with the idea as well! Oh this sucks, I've definitely done q(8) wrong. If I'd have worked that out, I would have got those easy marks!
Original post by extons
I think you had to use the value of P(X=2), after finding it, then making another binomial 'parameter'. So it then became Y~B (2, (P(X=2))). Then you calculated:

2C1 x (p(x=2)) x (1-p).

That's what I did anyway. May be totally wrong!

Edit::::: So final answer, I got was...0.399. Think I've seen that around earlier in the thread.


this
Original post by extons
I think you had to use the value of P(X=2), after finding it, then making another binomial 'parameter'. So it then became Y~B (2, (P(X=2))). Then you calculated:

2C1 x (p(x=2)) x (1-p).

That's what I did anyway. May be totally wrong!

Edit::::: So final answer, I got was...0.399. Think I've seen that around earlier in the thread.


Oh, I see! Thanks for clearing that up. I spent half an hour on that one question reading it over and over I ended up putting down the E(X) instead because I was so clueless haha! Either way this one was a resit for me, and it definitely went better than June 11 so it's all good.
Reply 154
Avatar for extons
extons
10
Original post by 22AcaciaAvenue
Oh, I see! Thanks for clearing that up. I spent half an hour on that one question reading it over and over I ended up putting down the E(X) instead because I was so clueless haha! Either way this one was a resit for me, and it definitely went better than June 11 so it's all good.


That's the thing with stats - the content is so easy but the disguise they often have on questions is annoying! Great once you overcome that first barrier though! Well done. :smile:
Original post by extons
I think you had to use the value of P(X=2), after finding it, then making another binomial 'parameter'. So it then became Y~B (2, (P(X=2))). Then you calculated:

2C1 x (p(x=2)) x (1-p).

That's what I did anyway. May be totally wrong!

Edit::::: So final answer, I got was...0.399. Think I've seen that around earlier in the thread.


I did exactly what you did but basically made a list of possibilities. It was that one had to be 2 (P(X=2) and one couldn't be 2, (P(X≠2)) and then just doubled that. So you got 2 x p(x=2) x p(x≠2) which is the same as 2C1 x p(x=2) x (1-p) :smile:
Reply 156
Avatar for extons
extons
10
Original post by LukeDPHart
I did exactly what you did but basically made a list of possibilities. It was that one had to be 2 (P(X=2) and one couldn't be 2, (P(X≠2)) and then just doubled that. So you got 2 x p(x=2) x p(x≠2) which is the same as 2C1 x p(x=2) x (1-p) :smile:


Nice one! There are so many weird and wonderful ways the mark scheme allows...I'm always happy to just find one! :smile:
Original post by Molly/21
Will probably still get a decent grade anyway as i go to a grammar school and nearlly everyone struggled with the last two questions. Even those who do Further Maths...


Its not too much of a bother redoing them in the summer. The minefield comes when you have to redo them in Year 13, (IF you have to redo them in 13) I applied to Cambridge this year, and the fact that I resat modules in Year 12 didn't really matter, it was the resits in January that basically killed my application there :P
Original post by extons
That's the thing with stats - the content is so easy but the disguise they often have on questions is annoying! Great once you overcome that first barrier though! Well done. :smile:


At the end of the day, I got 56% last time I did this exam :P And I'm confident I've smashed that this time :smile:
Reply 159
Avatar for extons
extons
10
Original post by LukeDPHart
At the end of the day, I got 56% last time I did this exam :P And I'm confident I've smashed that this time :smile:


I'm sure! Hope to see you on here on the 8th March. Ultimately having to resit this, or any other module for me, would be mad! Already got 6 initial exams lined up for June, inc. C3, C4 and M1 (doing Maths A level in a year) - I think any more maths would be the death of me! :tongue:

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