IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => GCE AS & A2 Level => Math => Topic started by: candy on May 27, 2009, 02:10:09 pm

Title: statistics
Post by: candy on May 27, 2009, 02:10:09 pm
50/50--------full marks
45+/50-------between 45 and 50
40+/50-------between 40 and 44
30+/50-------between 30 and 39
30-/50-------below 29
Title: Re: statistics
Post by: Rage2o9 on May 27, 2009, 08:52:09 pm
50/50, actually.
Title: Re: statistics
Post by: KillaInstinc on May 27, 2009, 09:47:27 pm
discuss all da qiestions....

last ques..wat did u get by observing...dat m-1/2s and m+1/2s

Title: Re: statistics
Post by: sahrhp on May 27, 2009, 10:00:13 pm
it was like 18.2-7.1 and 18.2+7.1 i dnt remember the values off the curve
Title: Re: statistics
Post by: Rage2o9 on May 27, 2009, 11:56:32 pm
it was like 18.2-7.1 and 18.2+7.1 i dnt remember the values off the curve

Did you get around 160 or so?
Title: Re: statistics
Post by: osmosis on May 28, 2009, 02:49:59 am
I got 160 too..... :)
Title: Re: statistics
Post by: eye-candy on May 28, 2009, 07:02:11 am
me 2.... :)
Title: Re: statistics
Post by: eye-candy on May 28, 2009, 07:14:41 am
ne1 remembers da answers to da 1st q??
Title: Re: statistics
Post by: isaac mendez on May 28, 2009, 07:23:57 am
i also got 160...
Title: Re: statistics
Post by: KillaInstinc on May 28, 2009, 07:35:15 am
wat was da 1st question ??
Title: Re: statistics
Post by: Rage2o9 on May 28, 2009, 10:13:57 am
The first question was finding the mean.
I got 997. What about you guys?
Title: Re: statistics
Post by: eye-candy on May 28, 2009, 10:16:58 am
ya evn i 996.8
wat abt da 2nd part of this q ??
Title: Re: statistics
Post by: Rage2o9 on May 28, 2009, 11:10:54 am
ya evn i 996.8
wat abt da 2nd part of this q ??

Should leave the answer to 3s.f. so 997.
Anyway, what was the second part of the question? I forgot.
Title: Re: statistics
Post by: eye-candy on May 28, 2009, 11:47:07 am
da prob dat exactly 2 of 3 chosen cartons hav volume greater den 1002

my ans ws like.....(.25*.25*.75)^3 =0.000103    ???
Title: Re: statistics
Post by: insane.kid on May 28, 2009, 11:58:48 am
oops i did 3C2 * .25^2 * .75 = .141 this is what i did for part ii) of question 1 ???
Title: Re: statistics
Post by: xcon89 on May 28, 2009, 12:27:35 pm
insane boy

you are right!!

and the guy above it, actually what you should have done is (0.25 x 0.25 x 0.75) and MULTIPLY by three! rather than cube it!

anyway you'll get one mark out of the two :)
Title: Re: statistics
Post by: eye-candy on May 28, 2009, 12:30:50 pm
ya...insane yur ans is correct..:)

stupid mistake
sh*t
Title: Re: statistics
Post by: eye-candy on May 28, 2009, 12:35:59 pm
i m a girl By the way!
lol
Title: Re: statistics
Post by: insane.kid on May 28, 2009, 12:50:28 pm
 ;D do u guys wanna discuss other answers i m ready to contribute  :)
Title: Re: statistics
Post by: sahrhp on May 28, 2009, 04:56:08 pm
Q PnC

i  i dont remember

ii 5!x6!
iii   (4!x3!)x2

Q zoo trip

p(elephant)=0.25
P(camel)=0.25
P(tractor) =0.50

den dere was this tree

P(frightened)= (0.25x0.6)+(0.25x0.7)+(0.50x0.8)

P(camel, given not frightened)=(0.25x0.3)/(1-P(frightened))
Title: Re: statistics
Post by: KillaInstinc on May 28, 2009, 05:57:31 pm
For The last ques..

Mean = 18.2

S.D = 14.2   
Title: Re: statistics
Post by: Rage2o9 on May 29, 2009, 01:34:37 am
Q PnC

i  i dont remember

ii 5!x6!
iii   (4!x3!)x2

Q zoo trip

p(elephant)=0.25
P(camel)=0.25
P(tractor) =0.50

den dere was this tree

P(frightened)= (0.25x0.6)+(0.25x0.7)+(0.50x0.8)

P(camel, given not frightened)=(0.25x0.3)/(1-P(frightened))


Answer for the first questiojn was a number which had like lots of 3s in it..
333333000 (something like that, cant remember)
Title: Re: statistics
Post by: ocean on May 30, 2009, 05:56:46 am
hey...i did some really stupid mistakes in the last questi0n...the last two parts actually...i couldnt find the mean and s.d. any idea how much marks it may cost me? i had found (summision-fx) and and (summision fx^2) correctly i know, but had divided it by some other number than (summision f) :S
Title: Re: statistics
Post by: eye-candy on May 30, 2009, 12:50:25 pm
i guess u will lose 2-3 marks in da 2nd last part
u will get all the marks in da last part if your method ws correct using the sd u got in the previous part
:)