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AQA Statistics 2 (B) Exam Thursday 21st June

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Original post by Taz123
HOw do you do it! Explain plz! Where do they get there numbers from!


Well basically you get the 0.24 divisor easily enough since thats the P(R+S is equal to or less than 8).

Then the numberator is the probability that r=4, AND that r+s<8, in otherwords, the probability that r=4, and s=4, and the probability that r=4 and s=3.
Reply 81
Original post by In One Ear
Well basically you get the 0.24 divisor easily enough since thats the P(R+S is equal to or less than 8).

Then the numberator is the probability that r=4, AND that r+s<8, in otherwords, the probability that r=4, and s=4, and the probability that r=4 and s=3.


Ohh i get it now! Thanks man!
If i could give you a kiss iwould but i cant but thanks!
Original post by Lollyage
Smooth operator :cool:


Haha you know it :wink:
After messing up in Fp3 and D1 I'm in real pressure to get as close to 100 as possible in this exam. I can do pretty much all of it the only problems I have is when I don't read the question properly or when an unorthodox question pops up and I really can't afford this to happen.

Sorry for the mini rant.
Reply 84
Well can someone help me with http://store.aqa.org.uk/qual/gce/pdf/AQA-MS2B-W-QP-JUN11.PDF 4c) please? I asked few hours ago but no one answered.. I don't get those questions, just now I did jan 2011, and very similar question, 4cii and 4ciii) and I couldn't it, I lost 6 marks again!http://store.aqa.org.uk/qual/gce/pdf/AQA-MS2B-W-QP-JAN11.PDF Please someone can you explain so that it would click to me... I even read whole probability topic s1 few times, but it still doesn't help me when I do these type of questions.
I would've gotten 72/75 on jan 2011, if not that part :/ In both papers same type of question and couldn't do both of them :frown:
(edited 11 years ago)
Reply 85
Original post by Miyata
Well can someone help me with http://store.aqa.org.uk/qual/gce/pdf/AQA-MS2B-W-QP-JUN11.PDF 4c) please? I asked few hours ago but no one answered.. I don't get those questions, just now I did jan 2011, and very similar question, 4cii and 4ciii) and I couldn't it, I lost 6 marks again!http://store.aqa.org.uk/qual/gce/pdf/AQA-MS2B-W-QP-JAN11.PDF Please someone can you explain so that it would click to me... I even read whole probability topic s1 few times, but it still doesn't help me when I do these type of questions.
I would've gotten 72/75 on jan 2011, if not that part :/ In both papers same type of question and couldn't do both of them :frown:


My method of remembering them is,
For P(X>a|X<b) = (P(X<b) - P(X>a))/P(X<b)
For P(X<a|X>b) = (P(X<a n X<b))/P(b)
For P(X<a|X<b) = P(X<a)/P(X<b)
Reply 86
Only just realised this thread exists! Woops!
Good luck to everyone tomorrow! :biggrin:
Reply 87
Original post by HappyBun
My method of remembering them is,
For P(X>a|X<b) = (P(X<b) - P(X>a))/P(X<b)
For P(X<a|X>b) = (P(X<a n X<b))/P(b)
For P(X<a|X<b) = P(X<a)/P(X<b)


Thank you A LOT! I will learn them all and practice before the exam, I know I said today in the morning that I can't apply if I don't understand, but now I understand that I don't understand it so that's the best method to remember. Thanks a lot again xD p.s. Sorry if my sentences don't make sense sometimes, this week was very intense with 3-4 hours of sleep, yesterday from 4pm till 4am papers, then 8am waking up today and papers up to now, so I am quite tired xD Will do the last paper, which I have done ages ago for the mock and get a good sleep so that i could wake up early tomorrow and and practice this. Sorry for the rant, went way too off-topic xD
Reply 88
Original post by Miyata
Thank you A LOT! I will learn them all and practice before the exam, I know I said today in the morning that I can't apply if I don't understand, but now I understand that I don't understand it so that's the best method to remember. Thanks a lot again xD p.s. Sorry if my sentences don't make sense sometimes, this week was very intense with 3-4 hours of sleep, yesterday from 4pm till 4am papers, then 8am waking up today and papers up to now, so I am quite tired xD Will do the last paper, which I have done ages ago for the mock and get a good sleep so that i could wake up early tomorrow and and practice this. Sorry for the rant, went way too off-topic xD


That's alright, hopefully they don't do a repeat of Jan 11 with all those nasty probability questions :/ Good luck tomorrow!!! :biggrin:
Reply 89
Original post by HappyBun
That's alright, hopefully they don't do a repeat of Jan 11 with all those nasty probability questions :/ Good luck tomorrow!!! :biggrin:


Thanks, you too!
Reply 90
I need to get 100 ums in this, otherwise the horrible s4 willmy maths grade!! Good luck to you all how are fighting against this exam
Good luck everyone! Hope you all get the grade you need!
Reply 92
Original post by HappyBun
My method of remembering them is,
For P(X>a|X<b) = (P(X<b) - P(X>a))/P(X<b)
For P(X<a|X>b) = (P(X<a n X<b))/P(b)
For P(X<a|X<b) = P(X<a)/P(X<b)


Hey, just want to confirm if this is correct:
For P(X>a|X<b) = (P(X<b) - P(X>a))/P(X<b) = (F(b) - F(a))/(F(b))
For P(X<a|X>b) = (P(X<a n X<b))/P(b) = (F(a)+F(b))/F(b)
For P(X<a|X<b) = P(X<a)/P(X<b) = F(a)/(F(b)

Or is it (F(a) * F(b))/F(b) for 2nd? But nah it isn't, is it? Because that would just be F(a)?
Original post by Miyata
Hey, just want to confirm if this is correct:
For P(X>a|X<b) = (P(X<b) - P(X>a))/P(X<b) = (F(b) - F(a))/(F(b))
For P(X<a|X>b) = (P(X<a n X<b))/P(b) = (F(a)+F(b))/F(b)
For P(X<a|X<b) = P(X<a)/P(X<b) = F(a)/(F(b)

Or is it (F(a) * F(b))/F(b) for 2nd? But nah it isn't, is it? Because that would just be F(a)?


I'm not 100% sure but doesn't the "n" represent "and" which is a multiply not an addition?
Reply 94
Original post by postman pat
I'm not 100% sure but doesn't the "n" represent "and" which is a multiply not an addition?


well then it would just be equal to F(a) because you times by b and then divide by b, so it wouldn't change. I am not sure as well, so hope someone will explain and/or my teacher will reply.
(edited 11 years ago)
Reply 95
Well what did everbody think of the exam? I found the last question really hard for some reason! =( but other than that seemed pretty straight forward. I've got all my answers stored on the calculator (ForTheWin) so if any body wants to compare, let me know.
Original post by Butdidudie
Well what did everbody think of the exam? I found the last question really hard for some reason! =( but other than that seemed pretty straight forward. I've got all my answers stored on the calculator (ForTheWin) so if any body wants to compare, let me know.


I found it nice! Apart from the last question which I did, but not sure if correct :s-smilie: also, the binomial on the poission I did wrong as I multiplied (0.27)^ 3 to the rest of it apart from adding :L if we could know what you got, then that would be lovely thanks! :smile:
Reply 97
I thought it was a nice paper but I wasn't sure about the last 2 parts on the last question (I think it's Q7. c)iii) and iv) maybe) :/ does anyone know how you were supposed to find the answer?
Reply 98
Original post by Skittles12
I thought it was a nice paper but I wasn't sure about the last 2 parts on the last question (I think it's Q7. c)iii) and iv) maybe) :/ does anyone know how you were supposed to find the answer?

I ended up just making up formuleas and substituting to get an answer that looked about right! 0.3125 and 0.5536 if your interested.
Original post by Butdidudie
I ended up just making up formuleas and substituting to get an answer that looked about right! 0.3125 and 0.5536 if your interested.


Didn't the answers to the last question need to be in exact form?

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