OCR MEI Statistics 1 (S1)

omfg i did 14 as well :/ x

Oh infact, it was 5 questions from section A and 9 from section B, 14 is right x

hey !!!!!
I totally agreee with everything u said !!!
Rejected h0
got that bionomial thing

an the 8%
was a total guess
for the i) i did 0.92*0.92*0.08
then the last paprt i think i did 1-(0.92^20)

the last blood coin question was hell wat did u do ????

Oh lord. Were you doing OCR *MEI* ???

for the last question u had to work out all the possibilities of 3 heads.. so u cud have 3 on the first go 0 next go 0 last go..
1,1,1
2,1,0,
0,3,0 ... etc and u had 10 possibilities, then using the probability table u just calculated the probabilities and added them

so it was 840/3003? people are scaring me with these figures. anyone can confirm this?

Yeah i was doing MEI.

so was the histogram about car engines?

Yeah i was doing MEI.

so was the histogram about car engines?

Yeah i was doing MEI.

so was the histogram about car engines?

Oh yeah... for the last question I did the whole multiplying and adding of:
1, 1, 1
1, 2, 0
0, 0, 3
But I forgot to multiply each one by the number of ways each one can occur or something... is that definitely what you're meant to do? I always get so confused with these... but that does make sense... though wasn't it only 3 marks?

Also for the "show that" on q7, the 2-mark and the 4-mark, I got both the answers but I barely wrote anything... I just had a line of working for each, eg. the 4-mark I think I put:
0.6*0.5^4 + 4*0.4*0.5^4 = 1.375
or whatever the numbers were... think I'll still get the marks? What else did they possibly want us to write? :|

Yes the histogram was about the volume of car engines.

you MAY lose one mark and no 4 marks for last question... what did u get for variance and expectation?

2.6 for E(X) and 8 for Var(X). Anyone else?

you MAY lose one mark and no 4 marks for last question... what did u get for variance and expectation?

This was the hardest exam I've ever done...I feel dissapointed at the moment
maybe it wasn't hard but still, I flopped it.
I'll probably get an E if im lucky

Wasn't Var(x) 8 - 2.6^2, = 1.24

Either that, or I did the 2.6^2 twice.

Oh, also, I didn't find it too bad as a paper. If someone has a copy of the paper, I can attempt to make a mark scheme this afternoon? Can't do it without a copy of the questions though; I can't remember them all...

Aaaahh maan I'm sorry to hear that, really- I just hope that it isn't your A2 year?

I feel, from talking to my friends and reading this thread and from doing all the past papers that this was indeed significantly harder.

June 2008 was quite hard- the grade boundary for an A was 53/72 , I think, which is very low at only 74%. I think that this paper had the harder types of questions from previous past papers.

For me the time constraint was ridiculous; an 8 mark hypothesis test AND a full on histogram AND a line or bar graph not to mention the huge figures regarding the car engine volumes require when calculating sum(x^2f) and sum(xf), etc.

Bummer.

So I think the grade boundaries will be even lower than 53/72

But that really depends on how most people felt about the timing and difficultly?