AS Edexcel S1 - (5th June 2015) Exam Thread

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Reply 1180

itsConnor_

What definitions do we need to know ?

Reply 1181

Kevin De Bruyne

Original post by PlayerBB

Help please?

Posted from TSR Mobile

TSR has a funny way of making images go upside down and inside out :colondollar:

But for your first question, on histograms the area represents a multiple of the frequency. Usually they give a histogram, give you the frequency for one bar (which you'll know the class width and f.d for) and you have to find the scale factor.

Reply 1182

jackharris_97

Original post by Gilo98

No worries, good luck for tomorrow - hope we get a Venn diagram Q for you!!

If we do you will be the first person I ask whether or not I got it right or not! Hahaha you too

Reply 1183

Maham88

what are the hardest past papers ??

Reply 1184

itsConnor_

How do I do part e) ? http://gyazo.com/d01162859bc997a1d62c1d91cbdd9c1e Jan 2015 (IAL) paper

ms here https://docs.google.com/file/d/0B23NLD5L6099MkJ1aHBxOFIxbUk/edit

:smile:

Reply 1185

Hai_Ann

Can anyone explain what each statistical model is good for?

A question from one of the Solomon papers was:

State, with a reason, whether or not the normal distribution might be suitable for modelling of each of the following:

i) the number of children in a family
ii) the time taken for a particular employee to cycle to work each day using the same route
iii) the quarterly electricity bills for a particular house

I saw a similar question to this in a past paper. I'm wondering is it necessary to know what a model is suitable or useful for?

Reply 1186

Ambrina

Original post by precious maro

where can I find Jan 2015 IAL?

and this is msc
http://static1.squarespace.com/static/52c1f91ee4b0a77a50337e61/t/55075711e4b0bc414e792c65/1426544732038/Edexcel+S1+January+2015+mark+scheme.pdf
qp in attachment

3.pdf352.4KB

Reply 1187

Shanahey

https://1a388b28f5ce9318f837a64962fc3ceab9c61da8.googledrive.com/host/0B1ZiqBksUHNYU2s1SVY1VDN2Q0U/June%202013%20(R)%20MA%20-%20S1%20Edexcel.pdf

Why is the numerator 0.35 in question 5c?

Reply 1188

u_s_e_r

Original post by Ambrina

and how do i do that?

the area of each bar is proportional to the frequency.
400 mini square in total represents 40 staff
so 1 staff is represented by 10 mini squares

hours freq (no of staff)
0-2 -- 16
2-5 -- 12
5-10 -- 6
10-20 -- 4
20-30 --- 2

the you use interpolation to work out the median
do you get it?

Reply 1189

Gilo98

Original post by jackharris_97

If we do you will be the first person I ask whether or not I got it right or not! Hahaha you too

Original post by Maham88

what are the hardest past papers ??

Jan 2015 IAL and June 2013 R

Reply 1190

Supermanxxxxxx

YESS 63/75 in the June 2014 r paper I was on a c yesterday woooo

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Reply 1191

particlestudent

How hard are people guessing it to be? Easier than C1 and 2?

Reply 1192

BrownieLover

Original post by Gilo98

Look at my posts over last few pages - been explaining it to someone else

yes thanks but i didnt get part (e)

Reply 1193

Gilo98

Original post by Shanahey

https://1a388b28f5ce9318f837a64962fc3ceab9c61da8.googledrive.com/host/0B1ZiqBksUHNYU2s1SVY1VDN2Q0U/June%202013%20(R)%20MA%20-%20S1%20Edexcel.pdf

Why is the numerator 0.35 in question 5c?

Because the area to the right of mew+15 is the only area on the graph which satisfies the probability of being greater than mew-15 but also greater than mew+15. Make sense?

Reply 1194

Ambrina

Original post by itsConnor_

How do I do part e) ? http://gyazo.com/d01162859bc997a1d62c1d91cbdd9c1e Jan 2015 (IAL) paper

ms here https://docs.google.com/file/d/0B23NLD5L6099MkJ1aHBxOFIxbUk/edit

:smile:

just square Y using the identity E(Y)^2 =E(3X-1)^2= E(9X^2 - 6X +1)
= 9E(X)^2 -6E(X) + E(1)
then substitute your valuesof E(X) and E(X)^2 and get the answer

Reply 1195

Thinking_Aloud

Original post by BP_Tranquility

But in the textbook, it says if you have y=10/x , and you find the value for the standard deviation of y, then the standard deviation for x is 10y so wouldn't the variance be 10²y?

Posted from TSR Mobile

I'm sorry, I can't find where it refers to that in the text book, did you mean to put y=x/10? If so and if you are working out variance from the standard deviation (instead of calculating it from the coded data and decoding, which is what I assumed), then you square it.
If you find the standard deviation of the coded data to be y, then you multiply by 10 to decode it, as you stated (10y). So then the variance would be the whole of that squared, so (10y)^2.

Reply 1196

IvoryToast

Hope so.
I got near full marks on c1 and c2 but can't do stats to save my life and haven't even done one paper or revised it since our last lesson 5 weeks back

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Reply 1197

Supermanxxxxxx

Original post by particlestudent

How hard are people guessing it to be? Easier than C1 and 2?

Easier then c1 and c2 but I reckon a few tricky question which could be worth a lot of marks

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Reply 1198

Ambrina

Original post by u_s_e_r

ohhh so then i find cumulative frequency and then median. woah that's a lot fo work for 2 marks >.> Thanks a lottt for taking the time to help! :smile:

Reply 1199