Statistics S1B 17/05/2013 Thread

OP

Have you got a mymaths login, that will probably be better than me trying to explain it!

ok

How's revision going for everyone?

There is always a question where you have to comment or suggest and that's where I seem to lose my marks

I have gone through all the past papers so I have learnt the mark scheme answers which I understand but I cant really do anything more

So can anyone throw me some of the worst or difficult questions they can think off?

This was posted from The Student Room's iPhone/iPad App

Reply 23

Original post by Son234

How's revision going for everyone?

There is always a question where you have to comment or suggest and that's where I seem to lose my marks

I have gone through all the past papers so I have learnt the mark scheme answers which I understand but I cant really do anything more

So can anyone throw me some of the worst or difficult questions they can think off?

This was posted from The Student Room's iPhone/iPad App

I have done all the AQA S1 past papers . Which years did you them from specifically ? Anything else that helped you understand the S1 module ?

Reply 24

ailish3park

Anyone got the jan 2013 past paper and mark scheme? :smile:

Reply 25

katie_evo

Original post by ailish3park

Anyone got the jan 2013 past paper and mark scheme? :smile:

http://www.mathspapers.co.uk/edexcel.html scroll down to s1, should be there :smile:

Reply 26

georgiaaaxo

8

could anyone please help me?
basically i'm fine with doing normal and binomial probability questions but get confused when they ask for a probability like this: P(5<x<10) for example. is there a general rule i can follow for normal, and another for binomial?
(i'm using a graphical calculator)
for normal do you always do just P(x<10) - P(x<5)? by finding z etc
for binomial it gets more confusing for me: can you do either p(x<= 9) - P(x<=5) OR p(x<=10) - p(x<=4)?
because the mark schemes seem to suggest this as they usually have two values for each and you can use either pair of values..howeverrrrr, i've just been doing q4 jan 2012 part a)iii) and it doesn't work! it gives two pairs of values in the marks scheme, and seems to suggest you can use either to get to the answer. however i used the second pair of numbers (0.9701 minus 0.2633) and it doesn't give me the right answer of 0.5 something :s-smilie:

any help appreciated!!!
thanks!

Reply 27

ailish3park

Original post by georgiaaaxo

could anyone please help me?
basically i'm fine with doing normal and binomial probability questions but get confused when they ask for a probability like this: P(5<x<10) for example. is there a general rule i can follow for normal, and another for binomial?
(i'm using a graphical calculator)
for normal do you always do just P(x<10) - P(x<5)? by finding z etc
for binomial it gets more confusing for me: can you do either p(x<= 9) - P(x<=5) OR p(x<=10) - p(x<=4)?
because the mark schemes seem to suggest this as they usually have two values for each and you can use either pair of values..howeverrrrr, i've just been doing q4 jan 2012 part a)iii) and it doesn't work! it gives two pairs of values in the marks scheme, and seems to suggest you can use either to get to the answer. however i used the second pair of numbers (0.9701 minus 0.2633) and it doesn't give me the right answer of 0.5 something :s-smilie:

any help appreciated!!!
thanks!

try using a mini number scale, marking off what numbers you need. e.g for P(x<10) - P(x<5), you want the numbers between every thing less than 10 and everything less than 5 so: 2 3 4 / 5 6 7 8 9 / 10 11 so it's P(x<=9) - P(x<=4)

Reply 28

AQA SS1B ... Please can someone help me with this question as I don't understand how the answers are mean = 7.7 and SD= 1.26 to 1.34

Thanks :biggrin:

Mr Stickler processes 32 applications each day. His records for the previous 10 days show that the numbers of photographs that he deemed unusable were
8 6 10 7 9 7 8 9 6 7

By calculating the mean and the standard deviation of these values, comment, with reasons, on the suitability of the 32, 0.15 model for the number of photographs deemed unusable each day by Mr Stickler. (4 marks)

Reply 29

OP

Original post by georgiaaaxo

could anyone please help me?
basically i'm fine with doing normal and binomial probability questions but get confused when they ask for a probability like this: P(5<x<10) for example. is there a general rule i can follow for normal, and another for binomial?
(i'm using a graphical calculator)
for normal do you always do just P(x<10) - P(x<5)? by finding z etc
for binomial it gets more confusing for me: can you do either p(x<= 9) - P(x<=5) OR p(x<=10) - p(x<=4)?
because the mark schemes seem to suggest this as they usually have two values for each and you can use either pair of values..howeverrrrr, i've just been doing q4 jan 2012 part a)iii) and it doesn't work! it gives two pairs of values in the marks scheme, and seems to suggest you can use either to get to the answer. however i used the second pair of numbers (0.9701 minus 0.2633) and it doesn't give me the right answer of 0.5 something :s-smilie:

any help appreciated!!!
thanks!

Also your graphic calculator has a feature where it can find the probability between two values for a normal distribution question

Reply 30

georgiaaaxo

8

Original post by ailish3park

try using a mini number scale, marking off what numbers you need. e.g for P(x<10) - P(x<5), you want the numbers between every thing less than 10 and everything less than 5 so: 2 3 4 / 5 6 7 8 9 / 10 11 so it's P(x<=9) - P(x<=4)

yeah i do use one but i still get a bit confused :P oh okay, so the other way doesn't always work? so you always have to work it out depending on the question? why do they include it in the mark scheme then :s-smilie:

thanks though!

Reply 31

May-o2q

14

Guys, I kno this thread is for aqa, but could anyone of u help me do this question? It's question 10. :frown:

ImageUploadedByStudent Room1368638395.262182.jpg

Posted from TSR Mobile

Reply 32

OP

Original post by Tha Realest

AQA SS1B ... Please can someone help me with this question as I don't understand how the answers are mean = 7.7 and SD= 1.26 to 1.34

Thanks :biggrin:

Mr Stickler processes 32 applications each day. His records for the previous 10 days show that the numbers of photographs that he deemed unusable were
8 6 10 7 9 7 8 9 6 7

By calculating the mean and the standard deviation of these values, comment, with reasons, on the suitability of the 32, 0.15 model for the number of photographs deemed unusable each day by Mr Stickler. (4 marks)

The sum of all the values is 77.

To work out the mean you divide the sum (77) by the number of values which is 10.
The answer then comes out to be 7.7 .

For the standard deviation I found this online which may help you.

1. Add up all of the data values.
2. Find the mean by taking the results of step one and dividing by the number of data points.
3. For each data point, subtract it from the mean and square the result.
All of the values from this step will be positive.
4. Add up all of the results from step 3.
5. Divide the result from 4 by the number of data points minus one. This will give you the variance.
6. Take the square root of the variance to get the standard deviation.

Your answer will come to roughly 1.27 .

For Binomial

Mean = np = 32 * 0.15 = 4.8
standard deviation = sqrt(np(1-p)) = sqrt(4.8*0.85)= 2.02

Reply 33

Son234

Original post by Tha Realest

I have done all the AQA S1 past papers . Which years did you them from specifically ? Anything else that helped you understand the S1 module ?

Jan 2009 onwards so that it matches the spec

Have you done the Jan 2013? I have the paper if you want

Also What revision material have you used?

Do you know how to estimate the binomial by the use normal

Basically use of continuity correction

Because it's rarely asked so there might be a good chance it comes up! :-)

This was posted from The Student Room's iPhone/iPad App

Reply 34

Original post by ollyhal

The sum of all the values is 77.

To work out the mean you divide the sum (77) by the number of values which is 10.
The answer then comes out to be 7.7 .

For the standard deviation I found this online which may help you.

1. Add up all of the data values.
2. Find the mean by taking the results of step one and dividing by the number of data points.
3. For each data point, subtract it from the mean and square the result.
All of the values from this step will be positive.
4. Add up all of the results from step 3.
5. Divide the result from 4 by the number of data points minus one. This will give you the variance.
6. Take the square root of the variance to get the standard deviation.

Your answer will come to roughly 1.27 .

For Binomial

Mean = np = 32 * 0.15 = 4.8
standard deviation = sqrt(np(1-p)) = sqrt(4.8*0.85)= 2.02

Thanks Alot ... I can't believe I got stuck on a simple question , I think I am not concentrating properly due to tiredness lol

Thanks Very Much ( appreciate the help ) :biggrin:

Reply 35

Original post by Son234

Jan 2009 onwards so that it matches the spec

Have you done the Jan 2013? I have the paper if you want

Also What revision material have you used?

Do you know how to estimate the binomial by the use normal

Basically use of continuity correction

Because it's rarely asked so there might be a good chance it comes up! :-)

This was posted from The Student Room's iPhone/iPad App

Same ... I have done January 2009 paper and onwards to January 2013 ( thanks but already done it lol ) ...

Are you going to do the AQA S1 2005-2008 papers by any chance ??

Cheers :cool:

Reply 36

OP

Original post by Son234

Jan 2009 onwards so that it matches the spec

Have you done the Jan 2013? I have the paper if you want

Also What revision material have you used?

Do you know how to estimate the binomial by the use normal

Basically use of continuity correction

Because it's rarely asked so there might be a good chance it comes up! :-)

This was posted from The Student Room's iPhone/iPad App

If you have the Jan 2013 could you upload it please!

Reply 37

Son234

Original post by Tha Realest

Same ... I have done January 2009 paper and onwards to January 2013 ( thanks but already done it lol ) ...

Are you going to do the AQA S1 2005-2008 papers by any chance ??

Cheers :cool:

Do you have the Mark
Scheme for the 2013?

And i would of done but I don't really have the time especially with other exams

Wbu?

I will post here in a few hours

a list of all the comment or suggest type questions

And we can go over the answers :-)

This was posted from The Student Room's iPhone/iPad App

Reply 38

Son234

Original post by ollyhal

If you have the Jan 2013 could you upload it please!

I will upload it in 1-2 hrs but i
don't have the Mark scheme unfortunately

This was posted from The Student Room's iPhone/iPad App

Reply 39