S1 Jan 12 Edexcel - Past Papers, Model answers, tips

Just what I was thinking :tongue:

hi can i ask in the JAN 2011 paper question 7)a) writing those missing probabilities they are tricky so how would u tackle those questions thanks

Reply 61

intellectual1

3

Original post by Relina

thnx alot

I know it might be disturbing but it appers that you have a very deep understanding to S1

so plz can you have alook at that link '' http://www.thestudentroom.co.uk/showthread.php?p=35852522&highlight=
here my question which I didn't get as book contradicts my answer so plz if you are free and can help do

my exam is after tomorrow.........thnx in advance :wink:

I've only read through all the examples and consolidated my understanding. Which past paper and question is it? The papers become more tricky and demanding from Jun08 onwards it seems.

Probability and the Correlation/Regression questions almost always have a huge number of marks. Its impossible to avoid the Normal Distribution questions as well.

I'll put up my notes and worked examples and answer any questions for the Summer sitting of this paper. The exam is on Tuesday, but I don't feel as prepared in this Winter session. Now I think I should've followed the advice of a friend and entered for the Summer instead. S1 is great, but S2 has extremely high grade boundaries. The problem with Statistics is the methods, make a small error and the entire question is wrong ah.

The topics highlighted in bold, are almost certainly likely to feature. We have a Venn Diagram in the Jun11 paper, so we should expect a huge Tree Diagram question for Probability. A rather tricky Normal Distribution one. They love to assess the Skewness stuff as well.

(edited 12 years ago)

Reply 62

al_habib

1

guys how do you go about this question , it may come up..am stuck on part b

Q.1. The continuous random variable Y is normally distributed with mean 100 and variance 256.

(a) Find P(Y < 80).

(b)Find k such that

P(100− k≤Y≤100+k)=0.5l6.

Reply 63

intellectual1

3

Original post by StraightUpG

Just what I was thinking :tongue:

Its not that deep of an understanding :tongue:

I was entered for this in Winter, I really wanted to do this when fully prepared in Summer.

I still feel though that the topics as the examiners cite in the reports that the Probability and especially Normal Distribution questions are where most marks are easily lost. We should expect a Probability Tree Diagram as there was a Venn Diagram only in the June11 paper. Normal Distribution is a topic that historically examiners write in their reports every year where candidates struggle the most. The understanding can be gained by actually working through all the examples in the textbook. Really think deeply and reflect and understand the examples. The most recent papers for Core AS Maths showed how there is a deeper understanding expected.

If you can do the following topics very well, you can gain a comfortable B grade, and an A or high A grade if you know the rest of them well too.

Probability
Normal Distribution
Correlation
Regression

Almost always there are marks to be gained from Correlation and Regression questions. Do the as many questions from past papers, especially from June 2008 paper onwards, as it is then more challenging than in previous sessions. Although it is obvious that the examiners are sure to set at least one or two questions which will be testing understanding :rolleyes:

(edited 12 years ago)

Reply 64

Halimaa

OMG I'm sooo relieved !! I actually thought the exam was tomorrow I'm here stressing out and I come across this thread -_____- .. Yeah I can be a bit of a doughnut sometimes! But at least I've got an extra 24 hours to revise I can sleep in peace now! :biggrin:

Btw guys there are worked solutions on examsolutions.co.uk the guy there has videos up and explains it really well... Hope y'all find it useful :biggrin:

Reply 65

POWW!

12

Original post by al_habib

guys how do you go about this question , it may come up..am stuck on part b

Q.1. The continuous random variable Y is normally distributed with mean 100 and variance 256.

(a) Find P(Y < 80).

(b)Find k such that

P(100− k≤Y≤100+k)=0.5l6.

S.d. is Var sqaure rooted
square root of 256 is 16
so mean is 100 and s.d. is 16
standardise it
then solve :smile:

Reply 66

StraightUpG

1

Original post by intellectual1

Its not that deep of an understanding :tongue:

I was entered for this in Winter, I really wanted to do this when fully prepared in Summer.

I still feel though that the topics as the examiners cite in the reports that the Probability and especially Normal Distribution questions are where most marks are easily lost. We should expect a Probability Tree Diagram as there was a Venn Diagram only in the June11 paper. Normal Distribution is a topic that historically examiners write in their reports every year where candidates struggle the most. The understanding can be gained by actually working through all the examples in the textbook. Really think deeply and reflect and understand the examples. The most recent papers for Core AS Maths showed how there is a deeper understanding expected.

If you can do the following topics very well, you can gain a comfortable B grade, and an A or high A grade if you know the rest of them well too.

Probability
Normal Distribution
Correlation
Regression

Almost always there are marks to be gained from Correlation and Regression questions. Do the as many questions from past papers, especially from June 2008 paper onwards, as it is then more challenging than in previous sessions. Although it is obvious that the examiners are sure to set at least one or two questions which will be testing understanding :rolleyes:

Ive done all the papers so i should be okay :tongue:

you should do some solomon papers aswell, they help your understanding of every topic in depth and make you think that extra bit!

Reply 67

themedicalgeek

12

Original post by al_habib

guys how do you go about this question , it may come up..am stuck on part b

Q.1. The continuous random variable Y is normally distributed with mean 100 and variance 256.

(a) Find P(Y < 80).

(b)Find k such that

P(100− k≤Y≤100+k)=0.5l6.

For part b - I think what they are saying is that the normal distribution graph is symmetrical so moving above 100 (the mean) and moving below will give the same answer (probability). Draw a normal distribution graph- mark a point anywhere above the mean line then label it K (just to make the idea clear in your head, the diagram isnt really needed). Then get z value for 0.516 and solve as normal to get K.

Hope this helps

Can someone verify this as I this is my first time sitting the exam so dont want to be giving wrong answers :/

Reply 68

POWW!

12

June 09

71/75 !!!! I'm gonna be so disappointed if I don't get >90 ums

Reply 69

Bright

11

Original post by POWW!

June 09

71/75 !!!! I'm gonna be so disappointed if I don't get >90 ums

I wish I got that! :frown:

Reply 70

0range

20

Original post by Bright

I wish I got that! :frown:

You still have a day to revise just wake up early 2moro and go library and try and finish all of Jan 08-11 papers and do the questions U get wrong again.

Reply 71

intellectual1

3

Original post by Bright

I wish I got that! :frown:

Tried to message you but it said "this user has exceeded the limit of messages" :rolleyes:

If you look at past papers, there are about 20 marks for the regression and correlation questions...if you know how to use the formulae you can gain those easily. Likewise, the Probability and Normal Distribution questions are worth about 30 or so marks, with the rest of the 25 marks easily attained from the understanding of the median, mean, mode, midpoint, class boundaries widths etc

Reply 72

Bright

11

Original post by 0range

You still have a day to revise just wake up early 2moro and go library and try and finish all of Jan 08-11 papers and do the questions U get wrong again.

I will do so, going to stay up tonight and try and learn! I have school tomorrow, skipping it obv! Thanks for the advice and good luck! :smile:

Original post by intellectual1

Tried to message you but it said "this user has exceeded the limit of messages" :rolleyes:

If you look at past papers, there are about 20 marks for the regression and correlation questions...if you know how to use the formulae you can gain those easily. Likewise, the Probability and Normal Distribution questions are worth about 30 or so marks, with the rest of the 25 marks easily attained from the understanding of the median, mean, mode, midpoint, class boundaries widths etc

Thanks! Yep will try and learn/do all of that tonight! ..and sorry about pm I'm just way too popular :wink:

haha kidding :smile:

Reply 73

intellectual1

3

Original post by Bright

I will do so, going to stay up tonight and try and learn! I have school tomorrow, skipping it obv! Thanks for the advice and good luck! :smile:

Thanks! Yep will try and learn/do all of that tonight! ..and sorry about pm I'm just way too popular :wink:

haha kidding :smile:

It can be done....get your S1 textbook go through the examples and the summary of key points:

Question on all these is absolutely certain...

1. Probability
2. Normal Distribution
3. Discrete Random Variables
4. Regression and Correlation - alot of easy marks if you know how to use the Sxx, Sxy, Syy formulae :wink:

5. Skewness, Outliers and Box Plots, Standard Deviation, Variance, Coding, Mid Point, Class width etc

If you begin now, you'll have reviewed all the examples within 6 hours, and make use of the textbook with the cd-rom of solutions :wink:

Probability Tree Diagram has'nt appeared in the Jun11 S1, which means it is certainly in Jan12 S1.

(edited 12 years ago)

Reply 74

Jack_Smith

8

Exam tomorro!! =/

Quite prepared i think but worried about loosing stupid marks on normal distrubution!! :/

Reply 75

exam2k10

9

Original post by Jack_Smith

Exam tomorro!! =/

Quite prepared i think but worried about loosing stupid marks on normal distrubution!! :/

Got a feeling that they may give us a simultaneous normal distribution question which requires us to find the value of the mean (meu) and standard deviation (sigma). I am fully prepared for normal distribution :biggrin:

and especially love the simultaneous normal distribution question.
When I did June 11 last year at AS, I did really badly because I did not have much knowledge on S1. Now, I have a great understanding and I feel that a tree diagram may come up but I can't guarantee anything. They may ask a question where you have to have the knowledge to predict which method to use for the given probability question.

Reply 76

Legendary

1

Time to learn the definitions. :colone:

Hopefully I won't make any mistakes tomorrow.

Reply 77

destruction

you see for quartiles should I use n+1/2 etc, because my teacher told us to do it by inspection but on examsolutions they using n+1/2 which gives them 14.5= 15th value but I would only get the 14th value

Reply 78

destruction

I would just do 1/4n for first quartile if it is a decimal like 2.3 round it up and it be the 3rd value, with 16 it be 4 and that one can be done by inspection