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

I really don't get that, can you tell me what the class width is - is it 5 because its in the 5< y <10 class... Would you be kind enough to do this question plsss

Any really hard papers?

As long as you didn't cross it out, you'd get the marks

Jan 2016 IAL and june 2015 .

where can i find jan 2016 ial?

where can i find jan 2016 ial?

Someone posted in on the thread here: http://www.thestudentroom.co.uk/showpost.php?p=65730797&postcount=266

Your 18.26 is the mean +1 standard deviation. You are asked to see how many plants are bigger than this. So you need to see how many plants are in the 15 to 25 interval are bigger than 18.26.
You need to know how many plants are bigger than 18.26 in this interval.
So find the fraction of the interval you have which is 3.26/10 (how far along the interval you are/ the interval size)
Multiply this fraction by 12 to see how many plants this is (3.91)
So the plants in the interval bigger than this is (12-3.91) = 8.09
Add the 4 plants in the higher interval is 12.09 (=12)
hope this helps

Here's how I did it:
1 standard deviation above the mean has a yield of 18.3 so you need to look at the group 15<y<25
So for normal interpolation you do
Lower bound + how far in group/frequency of group *class width =18.3
and so rearrange to get how far in the group=18.3 - LB /class width *frequency

So
15 + ?/12 * 10=18.3
rearrange ?=3.96
But this shows the number of plants that have a yield between 15<y<18.3
and you want above so in that group there are 12 plants so 12 - 3.96 + the extra 4 in the next group =12.04 so 12 plants.

Just found some notes I made a long time ago, and I don't recognise this equation from any past papers. Is there any chance that it could come up?

"Discrete uniform distribution: Var(X) = (n+1)(n-1)/12 = (n^2 - 1)/12."

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

When they say give an interpretation of b ,what is usually meant ?

Jan 2016 IAL and june 2015 .

do u have a link for Jan 2016 IAL? thanks

Is there a particular question that you find hard? One thing to remember that PMCC never changes with coding. Dont know if this helps?



Nope. Tree Diagrams arent always independent. So flipping a coin would be an independent event, since the second flip doesn't change dependent on the first flip. But boys and girls cycling to school would be dependent as the odds for cycling would go up, say, if you were a girl in comparison to if you were a boy.