This discussion is now closed.

Check out other Related discussions

Edexcel S2 Revision Thread

Noble.

No, they said calculate the probability that one of the lengths is >6. That happens if X is between 6-7, or between 1-4.

****.

Reply 381

Mahia

1

vc94

Hi guys, Here are my S2 solutions for your entertainment.

I've only lost marks in q3 then!!
I got a 1/3. reckonm i could get any method marks?

Reply 382

Andamiriel

10

Noble.

Except the definition of a critical region is 'the range of values that lead to the rejection of the null hypothesis, and the acceptance of the alternative hypothesis'. I really don't think the S2 examiners are stupid enough to ask such a question.

HAAA jesus ok. im sure it said something like that though :frown:

Reply 383

Noble.

17

Andamiriel

HAAA jesus ok. im sure it said something like that though :frown:

Not with the words 'critical region' it wouldn't.

Reply 384

sbaloch

Ok this is my attempt once and for all to appeal to logic regarding the rectangle question. This was my approach (which at least by my thinking is sound):

Short side = A (distributed between 1cm and 7 cm)
Long side = B (distributed between 3cm and 9cm)

The key thing to remember is that these distributions do NOT occur independently of each other. That is, if Side A is 1cm, Side B HAS to be 9cm and the same goes for all variations of lengths. This means the probability of side A being a certain length 'x' is EQUAL to the probability of side B being ' (20 - 2x)/2 ' <--- they are dependent upon each other.

From this alone you can eliminate all the answers that are appearing to suggest that you add P(X<4) and P(X>6) The fact remains that P(X<4) = P(X>6)

Working this out from Side A: the area beneath the continuous uniform distribution is (4 - 1)*1/6 = 1/2

Working this out from Side B: the area beneath the continuous uniform distribution is (9 - 6)*1/6 = 1/2

I hope I've explained this well enough and that you can understand my thought process. If you want to suggest something different please explain the wrong assumption in my method. Thank you :smile:

Reply 385

=) =) =)

What do people think the grade boundaries will be for this exam? There were quite a few hard bits in there..

Reply 386

The TSR Star.

11

Does anyone have the paper because I really can't remember the questions and I have no clue what you guys are on about...

Reply 387

Progashman

2710

Dont worry guys, I only need 5% so I just checked the MS and I got about 30%. Ill drag the grade boundaries down for ya :smile:

I need 5 UMS the least, by getting 30%, theres no way I can get below 5UMS right...even if I may have done the worst on the face of this planet :cool:

lol

How can you only need 5 UMS? Your other scores must have been like 95 for all 5!

Reply 388

Progashman

The TSR Star.

Does anyone have the paper because I really can't remember the questions and I have no clue what you guys are on about...

Posted 2 pages back by some guy.

http://www.thestudentroom.co.uk/attachment.php?attachmentid=86711&d=1276164606

Reply 389

laurenlodge

19

The TSR Star.

Does anyone have the paper because I really can't remember the questions and I have no clue what you guys are on about...

The paper is in the same link as the answers posted earlier on :smile:

thanks!!!!!!!!!!!!

Noble.

Except the definition of a critical region is 'the range of values that lead to the rejection of the null hypothesis, and the acceptance of the alternative hypothesis'. I really don't think the S2 examiners are stupid enough to ask such a question.

For question 3 (5marks),

I did P(X<4) and got that wrong as I multiplied 4 by 1/6.
I ended up with 2/3 (the right answer), drew the uniform distribution, and did one part of the solution. Where the side X is less than 4.
How many marks do you think I would get for that? Any chance the marker would just look at my final answer or assume that I meant to do the right thing? I think loads of people did the same thing as me though..

Apart from that, everything looks correct except I drew the p.d.f. with straight lines instead of a curve, but showed the peak and when it ends/begins. And maybe -2 marks for question one.

Reply 392

A*Student

that paper tortured me :-(

Reply 393

Jinxxeh

6

Motherfudgerrrr!!
I really shouldn't read these threads, I know they're bad for my self-confidence/health..

Also, eurghhhhhhhh, I finished it with half an hour left so I was just leisurely checking through my paper and then I realised I hadn't done Question 4)b) and I was like ASDFGHJJKLYI and the invigilator was like THE EXAMINATION IS OVER PENS DOWN and I was like nooooooo fml.
I mean, it was only 3 marks, but I knew how to do it.. If I had, like, two minutes I could've done it :bawling:

And for Q1)d) I just wrote X~B(100,0.35)
X = # of people voting for Dr Brown (or w/e his/her name was) in 100.
Goshdarnit.

And like so many others I got 0.5 in Q3. :facepalm2:

Reply 394

.:excel4100%:.

14

vc94

Hi guys, Here are my S2 solutions for your entertainment.

Thanks for that!! I had exactly everything the same

*fingers crossed* It could be 100% but I didn't understand what 1(d) was asking for so I wrote like over half a page of everything about sampling distribution, hopefully that 1 mark is in there :cool:

Reply 395

Noble.

17

TylerDurden

For question 3 (5marks),

I did P(X<4) and got that wrong as I multiplied 4 by 1/6.
I ended up with 2/3 (the right answer), drew the uniform distribution, and did one part of the solution. Where the side X is less than 4.
How many marks do you think I would get for that? Any chance the marker would just look at my final answer or assume that I meant to do the right thing? I think loads of people did the same thing as me though..

Apart from that, everything looks correct except I drew the p.d.f. with straight lines instead of a curve, but showed the peak and when it ends/begins. And maybe -2 marks for question one.

Not sure, but you definitely won't get the marks automatically for getting the right answer. If you've got the right answer by doing the wrong thing you'll probably get one A1 and an M1.

Reply 396

taimoorsohail

will there be an upgrade for the rectangle question? I hope so...

Reply 397

Kudos92

1

taimoorsohail

will there be an upgrade for the rectangle question? I hope so...

What do you mean by an "upgrade"

Reply 398

=) =) =)

For the hypothesis testing (9 marks) I got my original mean and variance wrong (dont know how :/ )
But my method was completely correct...how many marks do i get?

Reply 399

w3lshrugby

Whatever method marks there were...probably 3/4/5?

Edexcel S2 Revision Thread

Related discussions

Latest

Trending

Trending

Articles for you