Edexcel S1 - 15th June, 2016 [Exam Discussion]

Original post by iMacJack

Anyone offer some help with part F of this question please? I know this was in your paper @Zacken - any help please? Thank you!

0.25 is the probability that exactly two candidates get a merit.

So that 0.25^2. What's the probability that exactly 1 candidate passes but doesn't get a merit.

Multiply that by 0.25^2 and then account for the # of ways this count happen.

Reply 502

Original post by asinghj

You are told that c = Q3 + 1.5(Q3 - Q1)
So find Q3 (part b) and Q1 (part a)
Put the numbers into the equation.
Similarly for d (d = Q1 - 1.5(Q3 - Q1)

Person specifically asked for Q2(f).

Reply 503

beast709

What do you do in questions where the data changes and you have to show the effect on standard deviation, the correlation coefficient, Sxy... etc.

https://1a388b28f5ce9318f837a64962fc3ceab9c61da8.googledrive.com/host/0B1ZiqBksUHNYU2s1SVY1VDN2Q0U/June%202014%20(R)%20QP%20-%20S1%20Edexcel.pdf

Example here is 3f

Reply 504

heyitskim

5

For S1, there's types of questions where they state a number has been added or reduced. And then it asks you to state the effect made on the standard deviation, mean, IQR etc? Can someone please explain to me how to do these type of questions😩 I don't understand

Reply 505

Original post by Zacken

0.25 is the probability that exactly two candidates get a merit.

So that 0.25^2. What's the probability that exactly 1 candidate passes but doesn't get a merit.

Multiply that by 0.25^2 and then account for the # of ways this count happen.

Yeah I get that - I've got 3[0.25^2 * 0.75?] I can't see how it's (0.75-0.25) properly however? I don't quite understand the reasoning behind it

Reply 506

asinghj

Original post by Zacken

Person specifically asked for Q2(f).

Oh yeah, he had part c highlighted so I thought that was part f 😂😂😂

Reply 507

Philip-flop

18

Are we allowed to draw Normal and Standard Distribution diagrams in pencil for the exam?

Reply 508

Original post by iMacJack

Yeah I get that - I've got 3[0.25^2 * 0.75?] I can't see how it's (0.75-0.25) properly however? I don't quite understand the reasoning behind it

But 0.75 includes the probability that the third person gets a merit as well, in which case you'd get 3 merit marks when the question specifically wants exactly 2 merit marks. So the probability that the third person passes but does not get a merit is 0.75 - 0.25

Reply 509

Original post by Philip-flop

Are we allowed to draw Normal and Standard Distribution diagrams in pencil for the exam?

Yes.

Reply 510

Original post by Zacken

But 0.75 includes the probability that the third person gets a merit as well, in which case you'd get 3 merit marks when the question specifically wants exactly 2 merit marks. So the probability that the third person passes but does not get a merit is 0.75 - 0.25

But, why -0.25? Why not -0.01 or whatever? I'm being really stupid here I'm sure

Reply 511

metrize

18

Is p(a' n b') the same as p(a' u b')

Reply 512

anndz3007

Original post by asinghj

January 2016 IAL was quite challenging.

where did you get that paper from, i check edexcel website but login required ._.

Reply 513

metrize

18

Original post by iMacJack

But, why -0.25? Why not -0.01 or whatever? I'm being really stupid here I'm sure

75% pass the exam (this also includes getting a merit as they still pass)

Getting a merit is 25% of students

So just to pass and no merit is 0.75-0.25=0.5

Reply 514

S1 Mark Scheme.pdf526.6KB

Original post by anndz3007

where did you get that paper from, i check edexcel website but login required ._.

Here, Jan 16 attached

Original post by iMacJack

Here, Jan 16 attached

Markscheme

Reply 516

anndz3007

Original post by iMacJack

Here, Jan 16 attached

omg thank you so muchhh, gonna do it and june 15 tonight to prepare for the worst case scenario tmr lol

Reply 517

Original post by metrize

75% pass the exam (this also includes getting a merit as they still pass)

Getting a merit is 25% of students

So just to pass and no merit is 0.75-0.25=0.5

Okay but what I'm saying is even if they got 74% they'd still pass, but not get a merit, right? I'm a little bit confused...

Reply 518

anndz3007