S1 May 2012 - Post Exam Thread - Paper and Solutions in the FIRST POST

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thats what i did too!!

Actually, I did exactly what I did in the exam just now on a calculator and I got 0.07451 which is the answer, so I suppose we've got all the marks for that question? :biggrin:

Reply 181

A level Az

Original post by woodhamboyluke

P(F) is independent so you do P(P n S')xP(F) + P(P' n S)xP(F') + P(P' n S')xP(F)
If I recall, sure that's how I answered it

Yeah, I think what Arsey has done is used the answer in part b to make the calculation quicker, whereas we've just done it over again. It's right either way, so relieved :smile:

Reply 182

IrishPerson

Original post by A level Az

Actually, I did exactly what I did in the exam just now on a calculator and I got 0.07451 which is the answer, so I suppose we've got all the marks for that question? :biggrin:

OHH YESS!!! WOOOOOOooOO

Reply 183

IrishPerson

Pretty sure im just scraping an A...... but i got a high C in it last time so hopefully an increase of about 10 marks!! WOOO now just c3 and c4 to goooooooo

Reply 184

Miryo

for question 4, for the median, you've interpolated, You used 20, I used 15, which ones right?

Reply 185

Parthenon93

Original post by Arsey

Solutions now in the first post

For question 5, I found area using centimeters ... like 1cm x 1.5cm ... my k value came obviously different, but my frequencies came right. I got 90 in the first answer, the same table, the same mean, the same median. Is this still okay?

For question 7, in the tree diagram, instead of writing P' and S' prime I wrote out the words in the diagram and assigned them different letters like - splitting open (O); not splitting open (N). Would I lose marks for this?

(edited 11 years ago)

Reply 186

nabster

For question 5a I was concentrating so much on how to do the actual question that I missed the bit about exceeding the speed limit by 5mph so I used 30mph instead of 35. I ended up with 180 cars instead of 90. How many marks would I have lost?

Reply 187

arnab

dont think arsey predication is correct, the paper was easy but because of that histogram question, most people will LOSE a LOT of marks, potentally the full 13, if you couldnt do the first bit

grade boundary will most probably around 52-56 for an A.....my predication based on the last few past papers.

Reply 188

arnab

Original post by Al04

Okay there's 1 thing i don't understand.. the question that asks you to find the minimum thinning of the shell that results in death, given that pollutant levels above 16 are likely result in the death, how come you have to use 16 and not 17 as the value of p in your regression line? Since pollutant levels above 16 result in death, wouldn't you have to use 17?

exactly what i thought, so i used 16.1

Reply 189

arnab

lost 17marks overall, could have been only 2 but missread the information in 6C and got all of the histogram question wrong :'(

Reply 190

shahruk

Original post by Arsey

S1 May 2012

Not sure what to make of this paper, certainly required a little more thought than normal

Good luck.

Excuse me for being a noobie but I was wondering how do you get the QP so fast !? :colondollar:

Thanks though for taking the time out to give us an unofficial MS

(edited 11 years ago)

Reply 191

mandy12

Original post by Arsey

S1 May 2012

Not sure what to make of this paper, certainly required a little more thought than normal

Q1 - DRV

Easy

Q2 - PMCC

Easy

Q3 - Linear regression

Bit weird but pretty easy

Q4 - Venn

So stupidly easy

Q5 - Measures of location / spread

Very weird - you could have quite easily solved it by spotting that there were 22.5 5x5 squares so each 5x5 square represented 20 cars.

However I think this will be a massive bloodbath with many students picking up no marks.

Q6 - Normal distribution

Harder than normal I would say; I used the % points table to answer b) and c)

Q7 - Probability

Fairly easy but pretty unusual

I am going for

75 - 100ums
68 - 90ums
61 - 80ums
53 - 70ums
45 - 60ums
37 - 50ums
29 - 40ums

This thread will be locked at somepoint and then unlocked at midnight following the Stats 1 examination.

I will upload the paper and my solutions to this post.

I will do my best to answer questions about the paper but please try to read the thread first so that I am not answering the same questions lots of times.

Here are some links to previous S1 threads, they are worth a read and you will see what the common errors were...

S1 Jan 2012 - http://www.thestudentroom.co.uk/showthread.php?t=1865940

S1 June 2011 - http://www.thestudentroom.co.uk/showthread.php?t=1619124

The second link contains loads of past papers, model answers etc

Good luck.

i couldn't view the mark scheme..

Reply 192

kitriviolet

its in the attachment (:

Original post by mandy12

i couldn't view the mark scheme..

Reply 193

kitriviolet

ok for that one asking about whether youd use mean or median, i stupidly ignored that the whole thing was skewed and put it would not be affected by extreme values :frown:

Reply 194

Charlesworth

For once, I think a maths exam has gone good! Put a bit less pressure on me for C4. The histogram question threw me off at first, took me quite a while to work out what to do, even then I wasn't sure if I was doing it right!

Reply 195

Zhy

Only S3 and S4 to go and stats is done!!

Reply 196

shahruk

Original post by Parthenon93

Yea yea is totally fine! :biggrin:

The value of k depends on what 'scale' (you used centimeters, i just used 1,2,3 on the y-axis) you have used, but the frequency will remain same because :

frequency = k x area => if you calculate a large area by taking a large scale, your value of k will be smaller. but frequency is constant

And the tree diagrams ok too ! I did the same thing, as long as you mention which letter is which, shouldn't be a problem.

Reply 197

baggyyo

I think 75/75. YES!!! But I found the paper easier than most... much better than the M1 in termss of wording anyway.

Reply 198

Zhy

I got full marks I think, my regression line might be a bit inaccurate though (but it passed through the mean point).

Reply 199

tommyridges

I reckon I've got 73/75 there, the only question I think I've lost marks on is 5c) because when interpolating I took the lower bound as 19.5 and apparantly you're not meant to :rolleyes: