AQA S1B 17th May 2013 AM - Unofficial Markscheme

Scroll to see replies

Reply 20

t.adur

anyone got a copy of the question paper???

Reply 21

theo3335796

Original post by bleap

For the very last question, why was the answer not (1- the previous answer)^10 and also, how many marks would you expect me to lose for doing this method rather than the correct one as stated in the mark scheme?

Because the previous answer is for 10, whereas this question asks for each, so you have to work out the probability for one then do it the power of 10.

Not sure on the number of marks though.

Reply 22

theo3335796

Original post by t.adur

anyone got a copy of the question paper???

Refer to this thread, it's the third and fifth post

http://www.thestudentroom.co.uk/showthread.php?t=2348775&page=17&page=17

Reply 23

Jp1234

does anyone remember what they put for 4biv?

Reply 24

jp1302

"2b) (3)"

"4ciii) y = 0.46 + 1.00(1)x (3; Answers of 0.6 for 'a' will be penalised)"

What's the answer to 2b? Also how many marks would you reckon they'll give if I put,
y=0.6+1x

Reply 25

maggiehodgson

Original post by t.adur

anyone got a copy of the question paper???

There is another AQA ss1B thread (not labelled official mark scheme) and the whole paper appears on that. Can't remember which page of thread but it's quite a way in.

Reply 26

t.adur

Original post by theo3335796

Refer to this thread, it's the third and fifth post

http://www.thestudentroom.co.uk/showthread.php?t=2348775&page=17&page=17

Urm I checked the whole thread, the questions aren't there...

Posted from TSR Mobile

Reply 27

Gotzz

Original post by t.adur

Urm I checked the whole thread, the questions aren't there...

Posted from TSR Mobile

This is a link to the actual post:
http://www.thestudentroom.co.uk/showthread.php?t=2348775&page=17&p=42666664#post42666664
The questions are uploaded images of the paper.

Reply 28

t.adur

Original post by Gotzz

This is a link to the actual post:
http://www.thestudentroom.co.uk/showthread.php?t=2348775&page=17&p=42666664#post42666664
The questions are uploaded images of the paper.

ohh! thank you so much

Posted from TSR Mobile

Reply 29

PrinceUpsb

Original post by Jp1234

does anyone remember what they put for 4biv?

An entire page of waffle with the main points being: likely to be accurate because r=0.98 and the actual value is similar to y=a+bx value

Reply 30

Jp1234

Original post by PrinceUpsb

An entire page of waffle with the main points being: likely to be accurate because r=0.98 and the actual value is similar to y=a+bx value

Sorry i meant 5biv, what did you get for that?

Reply 31

PrinceUpsb

Original post by Jp1234

Sorry i meant 5biv, what did you get for that?

I really can't remember the value. While I was doing it though, I felt really confident when answering so if all is well I got the same value that this mark scheme says!

Reply 32

Ferrari_1996

For the Normal Distribution questions I thought you had to change them to <= because in the formula booklet it says that it gives the probably when the variable Z is "less than or equal to z." This means I lost some easy marks. For example, instead of plugging x = 425 in the formula I plugged in 424. I mean, if you use logic, you'll think that less than 425 means equal to or less than 424. Think about it, if something is less than 425, it's less than or equal to 424, right? Unfortunately, using logic doesn't work for the Normal Distribution :frown:

(edited 10 years ago)

Reply 33

Dingo749

Original post by jp1302

"2b) (3)"... What's the answer to 2b?

2b) Find the value for x when P(X<x) = 0.98 [with mean 421 and standard deviation 2.5]

Use the formula Z = [x-(Mean)] / Standard Deviation

So, 2.0537 = (x-421) / 2.5
=> x-421 = 5.13425
=> x = 426.13425 or 426.1 (to 1d.p.)

(edited 10 years ago)

Reply 34

Dingo749

Original post by Ferrari_1996

Normal Distributions use continuous data so that includes values such as 424.5 and 424.9999999999999999... that's why you need to use less than or equal to 425.

Reply 35

Ferrari_1996

Original post by Dingo749

Normal Distributions use continuous data so that includes values such as 424.5 and 424.9999999999999999... that's why you need to use less than or equal to 425.