# OCR MATHS PURE + STATS A-LEVEL official threadWatch

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#1
How are u guys feeling about tomorrow?

This thread can be used as an unofficial markscheme after the exam too
0
#2
Personally I’m hoping there’s not too much probability and a fat hypothesis test please
1
6 days ago
#3
For median is it n+1/2 and is Lower quartile 1/4(n+1)
0
#4
How did everyone find it
0
5 days ago
#5
1239 for the last question (value of n) P(x<n)

I think the Parametric hit x axis at around 8sqrt3/3 potentially iirc.

The u = 6x^2 + x I think I got 1/2 and -1/3

The standard deviation of 67-77g with mean 72g I think the question said, I believe I got 7.41

What did people get for the pollution hypothesis test?
1
5 days ago
#6
Yeah I got the exact same as u except for the last one, I can’t remember what I got for that
(Original post by CALLUM2412)
1239 for the last question (value of n) P(x<n)

I think the Parametric hit x axis at around 8sqrt3/3 potentially iirc.

The u = 6x^2 + x I think I got 1/2 and -1/3

The standard deviation of 67-77g with mean 72g I think the question said, I believe I got 7.41

What did people get for the pollution hypothesis test?
0
5 days ago
#7
Centre of circle was (3,-4) and radius 2
Volume of cylinder was like 5.0something
Hypothesis test was not significant
0.06something was p bag had less than 530g
5/11 was the p(a 2 | T=7)
44/225 was p(T=7)
Parametric hit axis at 8sqrt3/3
1 + 1.5x -9/8 x^2 + 27/16 x^3
Median of data was 65, IQR was 15, mean was 69 (hehe), standard deviation was 10.5
3
5 days ago
#8
Did anyone get 5.20 for the volume?
1
5 days ago
#9
What r value did u get
(Original post by NihilisticBear)
Did anyone get 5.20 for the volume?
0
5 days ago
#10
For the normal hypothesis test about pollution, I think it was two-tailed and I got the result was insignificant
1
5 days ago
#11
Yes!
(Original post by NihilisticBear)
Did anyone get 5.20 for the volume?
0
5 days ago
#12
4th root of 32/6 or something like that
(Original post by LexiV)
What r value did u get
1
5 days ago
#13
Just realised I stupidly forgot to sub. back the value of r into the formula for volume!!!
But I found Stats less time pressured and easier than Pure... which was weird as that never happens for me
2
5 days ago
#14
What was the method/working for the proof?
0
5 days ago
#15
For the one about the binomial expansion, did anyone get x=34, which wasn't even in the range of x values? I carried out the expansion using x=34 and got something completely different to sqrt(103), I looked at the question for so long wondering whether I was wrong or whether we were supposed to prove the expansion wasn't valid? Did anyone get the same?
5
5 days ago
#16
YESS I got the exact same I was so confused
(Original post by NihilisticBear)
For the one about the binomial expansion, did anyone get x=34, which wasn't even in the range of x values? I carried out the expansion using x=34 and got something completely different to sqrt(103), I looked at the question for so long wondering whether I was wrong or whether we were supposed to prove the expansion wasn't valid? Did anyone get the same?
2
5 days ago
#17
(Original post by NihilisticBear)
For the one about the binomial expansion, did anyone get x=34, which wasn't even in the range of x values? I carried out the expansion using x=34 and got something completely different to sqrt(103), I looked at the question for so long wondering whether I was wrong or whether we were supposed to prove the expansion wasn't valid? Did anyone get the same?
Yes! Just assumed my method was wrong
0
5 days ago
#18
I did proof by contradiction, assume that it was prime, then I said, let n=2k, where k greater than 2, then I put 2k into the equation 2^n - 1, which simplified to (2^k+1)(2^k-1), which was a product of 2 numbers, so not prime, so basically I said by contradiction, that her statement was correct
(Original post by CALLUM2412)
What was the method/working for the proof?
0
5 days ago
#19
What you had to do it use 0.01 so then it was (1.03)^0.5 then it’s sqrt(103)/10 so just time the answer by 10. I started with 34 and realised it was wrong
(Original post by NihilisticBear)
For the one about the binomial expansion, did anyone get x=34, which wasn't even in the range of x values? I carried out the expansion using x=34 and got something completely different to sqrt(103), I looked at the question for so long wondering whether I was wrong or whether we were supposed to prove the expansion wasn't valid? Did anyone get the same?
0
5 days ago
#20
The range value of K for the probability of young people vs old people in said something like 1/6 <= k <= 3
Not sure why again

And why would the data be useful for university students? (1)
And is it reliable? (2)
0
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