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Edexcel S2 Exam Paper January 2011 14/01/11

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Reply 380
For question 5(a)

Would you not get marks for showing the area under f(x) = 0, so I integrated between the limits of 0.5 and 0 and showed the area is equal to 1 !!! (which is a condition of a p.d.f.)
Reply 381
im guessing ill get a 0 in question 2 :frown:
Reply 382
Original post by Gibbo81
Q7
All done.
Any comments or corrections let me know.


I agree with all your answers. Thanks for putting up your solutions. :smile:
Original post by Gibbo81
Q7
All done.
Any comments or corrections let me know.

As far as I can tell they look correct (although I got the same as you for every question so not exactly a good source lol)
I missed last question last part:frown:
For some reason I did for P(X<=2):frown::frown::frown:
for 6e i used P(Z<15....) because i thot since it was <...15 was alright...although i did it 14.5 way and then crossed it out...will i get any marks at alll?
Original post by Gibbo81
Q7
All done.
Any comments or corrections let me know.


Agreeing with all :smile:
Original post by Geniusmiss
for 6e i used P(Z<15....) because i thot since it was <...15 was alright...although i did it 14.5 way and then crossed it out...will i get any marks at alll?


You will lose 1/2 marks for not using the 0.5 continuity correction. But that's as far as it goes. But if P (Z<15) nope....unless that was for X?
(edited 13 years ago)
Original post by snowflakesblues
You will lose 1/2 marks for not using the 0.5 continuity correction. But that's as far as it goes. But if P (Z<15) nope....unless that was for X?

sorry yeah it for X...P(X<15)
Original post by Geniusmiss
sorry yeah it for X...P(X<15)


Yeah, in that case, they usually take off 1 or 2 marks for not using the 0.5 continuity correction. Depends how strict they are. My teacher once, stripped off all my marks before for not using that. But I doubt they'd be so strict in an exam :smile:
Reply 390
For 5a could you have done f(0) and f(0.5)?
Reply 391
Thanks for posting your solutions Gibbo81 :borat:
Reply 392
i haven't read every-ones posts so sorry if this has already been asked...
but did anyone do poisson on the very last question?

i got something like .4779 as the probability, then multiplied by 3, to get x~Po(1.5ish) then used this....??
Original post by dolly88
i haven't read every-ones posts so sorry if this has already been asked...
but did anyone do poisson on the very last question?

i got something like .4779 as the probability, then multiplied by 3, to get x~Po(1.5ish) then used this....??


Nope my dear, n has to be large and p has to be small in order for it to be approximated by a Poisson. By large, n should've been at least 100 and p at least 0.05 or something...
Reply 394
Original post by dolly88
i haven't read every-ones posts so sorry if this has already been asked...
but did anyone do poisson on the very last question?

i got something like .4779 as the probability, then multiplied by 3, to get x~Po(1.5ish) then used this....??


the thing is I'm not sure this would be very accurate because n isn't large and p isn't particularly small...
Reply 395
On an unrelated note
im doing 9 modules which are - c 1-4 s 1-3 and fp 1 and 3
my teachers say its A level mathematics and AS Further maths
can someone please tell me which modules count as mathematics and which ones as further maths ?
Reply 396
Original post by Firaila
the thing is I'm not sure this would be very accurate because n isn't large and p isn't particularly small...


yeah that's what i thought!
the stupid thing is that i did binomial first of all, but couldn't quite get it to work cos it was such an awkward number..
oh well!
Thank you so much for putting your solutions on. Fell a lot more confident now and i wouldnt be suprised if the grade boundaries are a bit high
Original post by aneesh
On an unrelated note
im doing 9 modules which are - c 1-4 s 1-3 and fp 1 and 3
my teachers say its A level mathematics and AS Further maths
can someone please tell me which modules count as mathematics and which ones as further maths ?


Normal A level Maths needs 4 cores minimum. The remaining two can be ANY AS Modules. It's usually S1,M1,or D1.(the 1's are usually As Modules)
Further Maths consists of mainly A2 Modules. You'd need at least 2 cores in them. FP1,FP2 or FP3. You're allowed to shuffle with any other A2 Modules except C3 and C4. You are allowed to take some As Modules along with Further Maths, but it decreases your chances of getting an A* overall in FM. So in your case. Further Maths can come from. FP2-3 and S2, S3.

P.s You need 6 modules to make up an A level. So you might need a couple more As modules in there. It's worth just taking up 1 or 2 more As modules, as you get an extra A level as opposed to only an As...
(edited 13 years ago)
Reply 399
Sorry to post this again but on question 5(a) would you still get marks for integrating the f(x) between the limits of 0.5 and 0 and showing that the area under the curve is equal to one (which is a condition of a p.d.f.)

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