Edexcel S1 - 15th June, 2016 [Exam Discussion]

When doing histograms and stuff. For calculating the width of the bars or for like area of the bars. Do you always go +/-0.5 of the two boundary numbers ( e.g. bar goes from 5 to 10 on the x-axis, so you take width to be 6 and not 5 as its 4.5-10.5). I am just confused by this (when do it) as in some questions you do it and some you don't.

If they use Values where Classes "share numbers" (so 60 is "in" the First Class and "in" the Second Class) like this:Then the Class Width is just 5. BUT if the Classes look like this...Then you use rounding.

VV

Ah okay that makes sense, thank you! Also anyone walk me through/roughly tell how you do part F and G of Question 7 on the June 2013 (R) Paper please? Do you always have to draw a table in questions like that or is there another (preferably shorter) method?

Would appreciate it if someone could clarify how you get from step 1 to step 2 regrading y = a +bx.Step 1: f-100 = -0.424649..+ 0.395.. (m-100)Step 2: f= 0.735 +0.395m

When there's an outlier, what becomes the 'new' max/min value?
Is it the the next value in the data, which isn't an outlier?

The way I did it

(f) Worked out the probability that S1 =1 which was 0.2
Worked out the probability that S2 was 4 or less which was 0.8
Multiply = 0.16

And then g the way they do it in the mark scheme.

It's impossible if those are your values... What's the question?

HEY can someone pls help me with june 2013(R) question 3 part e) I got 18.26 but I don't understand how to interpolate and get 12.. Here's the paper's link: http://qualifications.pearson.com/content/dam/pdf/A%20Level/Mathematics/2013/Exam%20materials/6683_01R_que_20130517.pdf

How do you do question 5b in this paper: https://0120b046f61e7ee5f95eb13150514beb86ae661f.googledrive.com/host/0B1ZiqBksUHNYTWtJbXRsQTFDbEE/for-Edexcel/Solomon%20C%20QP%20-%20S1%20Edexcel.pdf

AND........

How do you do question 1 in this paper. I can't really picture how the tree diagram would look like
https://0120b046f61e7ee5f95eb13150514beb86ae661f.googledrive.com/host/0B1ZiqBksUHNYTWtJbXRsQTFDbEE/for-Edexcel/Solomon%20K%20QP%20-%20S1%20Edexcel.pdf

I haven't done the question, but your 18.26 looks like a great number as you need to see how many plants are bigger than this. If you look at 18.26 you will see that it is roughly 1/3 along that class width (you can work it out exactly). That leaves you with 2/3 (=8 plants) + the 4 plants of the next class width make the total 12

Q3 part (b)

http://qualifications.pearson.com/content/dam/pdf/A%20Level/Mathematics/2013/Exam%20materials/25_S1_June_2005.pdf

HEY can someone pls help me with june 2013(R) question 3 part e) I got 18.26 but I don't understand how to interpolate and get 12.. Here's the paper's link: http://qualifications.pearson.com/content/dam/pdf/A%20Level/Mathematics/2013/Exam%20materials/6683_01R_que_20130517.pdf

If in my working out the correct answer is shown, then afterwards i put something incorrect (such as the answer being 0.9772 but afterwards i did 1-0.9772=0.0228) would they ignore the incorrect or penalise me?