S2 Edexcel Thursday 24th May AM - PAPER & SOLUTIONS IN FIRST POST

I think 62 for an A.

A lot of people, including myself, made the silly mistake of using a poisson on the last question. But grade boundary people judge on the "quality of performance" not the ease of making a stupid mistake, so the fact that half of candidtates used poisson, losing 8 marks, won't have a massive dent due to the ease of the other questions. Overall, boundaries a little higher than they aim for (60) at 62.
it might not be 75 for 100 UMS, but it has been on nearly every S2 paper for ages, so I think max 74 for 100 UMS.


But the key information was 3 out of 5 Therefore, fixed number of trials, binomial p=0.6.

To be perfectly honest, it wouldn't be uniformly distributed at all. He's much less likely to post during early hours of the morning as it's likely he'll be asleep. It thus upsets me you suggested such a model.

i was surprised there was no definition questions, which im happy about

Pretty much the same with every s2 question.
Like the length of a call at a call centre (likely to be really short or long)
Cutting a piece of string (if it's near to either edge someone's gunna lose a finger)
I think the idea of them is just generally stupid

LAST GRADE BOUNDARIES

Session 100 90 80 70 60 50 40
Grade A* A B C D E
Jun-01 75 68 60 52 45 38 31
Jan-02 69 63 57 51 45 40 35
Jun-02 72 65 58 51 44 37 30
Jan-03 70 64 58 52 47 42 37
Jun-03 71 64 57 50 44 38 32
Jan-04 73 67 61 55 49 43 38
Jun-04 75 70 64 57 50 44 38
Jan-05 70 63 56 49 43 37 31
Jun-05 75 68 61 54 48 42 36
Jan-06 73 66 59 52 45 39 33
Jun-06 75 71 66 58 50 43 36
Jan-07 75 71 66 58 50 42 34
Jun-07 75 69 63 55 48 41 34
Jan-08 75 69 62 54 46 39 32
Jun-08 75 70 65 58 51 44 37
Jan-09 75 70 65 57 49 41 33
Jun-09 75 69 62 54 46 38 30
Jan-10 75 70 65 57 50 43 36
Jun-10 75 68 62 54 46 38 31
Jan-11 75 72 69 62 55 48 42
Jun-11 75 67 59 50 41 33 25
Jan-12 75 70 66 60 54 48 43

LAST GRADE BOUNDARIES

Session 100 90 80 70 60 50 40
Grade A* A B C D E
Jun-01 75 68 60 52 45 38 31
Jan-02 69 63 57 51 45 40 35
Jun-02 72 65 58 51 44 37 30
Jan-03 70 64 58 52 47 42 37
Jun-03 71 64 57 50 44 38 32
Jan-04 73 67 61 55 49 43 38
Jun-04 75 70 64 57 50 44 38
Jan-05 70 63 56 49 43 37 31
Jun-05 75 68 61 54 48 42 36
Jan-06 73 66 59 52 45 39 33
Jun-06 75 71 66 58 50 43 36
Jan-07 75 71 66 58 50 42 34
Jun-07 75 69 63 55 48 41 34
Jan-08 75 69 62 54 46 39 32
Jun-08 75 70 65 58 51 44 37
Jan-09 75 70 65 57 49 41 33
Jun-09 75 69 62 54 46 38 30
Jan-10 75 70 65 57 50 43 36
Jun-10 75 68 62 54 46 38 31
Jan-11 75 72 69 62 55 48 42
Jun-11 75 67 59 50 41 33 25
Jan-12 75 70 66 60 54 48 43

I happen to be an expert string cutter and I am disgraced by your lack of knowledge on the subject. I'll have you know i once cut a 20cm length of string into 0.0000001cm parts!

Yeah, I LOL'd inside when I saw the q in our paper was on sweet length.... wtf?

You must be the master of "pin the tail on the donkey".

Note to self, start measuring lengths of strawberry laces bought and use a hypothesis test to test whether a particularly short one is significant. If so, complain

Argh I did this too

Hye I did binomial crossed it all out then did poisson realising as soon as i gave the paper that it was probably binomial..
My question is is I used Poisson and using my model did the right technique for the first 2 parts right and did a bit of workign out for the last question so will I get atleast a few method marks?

Also talking of the question on que times where it said the probability that random customer has to wait at least
half a minute more than the mean( which was 2)
Would it not be P(X<= 1.5) + P(X>=2.5) ?