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

1. (Original post by iMacJack)
Probability of Rebecca and Sarah winning i got like 0.475 and 0.375 can't remember which order and e(r) = 0.45

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Yep exactly.
2. [QUOTE=gracebromby;65797221]Because didnt you have to multiply the 40 and 37 by the corresponding probabilities for each value and then add them together?[/QUOTE\
that's what i thought but i'm not sure
3. What's the highest and lowest grade boundary for an A so far?
4. (Original post by mibz515)
How can it be 17 when the frequency of the class width was also 17 people, Who got 8.5cm/34cm
because the width x the height needed to equal half the frequency, so width of 0.5 x 17 equalled 17 frequency
5. I think I put the PMCC deceased because the point was further away from the line of best fit?

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6. (Original post by leobrave)
61 for A?
7. (Original post by zandneger)
1.
Can't remember part a)
b) wiggles were the response variable as they are what changes based on the distance
c) the regression line I got was 0.722+0.014d
d) I subbed in 350 and got w=5.69
my answer was reliable because it was within the range of data

2.
a) 2p+Q=0.5
b) Q=0.15 P=0.175
c) 2.2 something like that?
d) E(R) =0.45
e) Sara's chance = 0.475 Rebecca's chance = 0.375

3.I don't remember much about this question other than the PMCC being around -0.7 and the extra data causing the PMCC to increase because it showed a positive correlation.

4.
a) 0
b) t=0.03
c) u=0.22
d) 0.45 and 15/37
e) 33 customers ordered dinner

5.
a) median baby weight was 3.47
b) s.d was 0.689
c) showed mean was 3.43
d) used that guys normal distribution to get that 0.2546 babies were under 3kg
e) showed that in the table only 9 babies were under 3kg whereas using his distribution I got that 12 babies were under 3kg hence he is wrong to assume the distribution

6.
a) 6.68% of men took over 300 minutes
b) the speedy chap needed to run his marathon in under 206 minutes
c) the probability was 0.18/0.5 (0.36)
how are you able to remember this all wow. en waarom heet jij zandneger.
8. (Original post by gayasfxckname)
That was one of the worst Statistics papers. I couldn't even answer the last two questions
The last two were very similar to last years paper

I had just done them again the other day so I think I got it right

For the last question you wrote out the coniditonal probability formula, then for the bottom half it was 0.5 as this was P w was greater than the mean. Then for top half of it yyou look at the previous bit of info it mentioned, which said probability that X was less than W when W was Mean +30.... this was 0.8412 or whatever... you take 0.5 to work out the distance to the mean and then look at your answer now and it is were it was less than the mean - 30 .... you have calculated the probability from 30 to the mean just before by doing that 0.8412 - 0.5.... so this would be the right hand side of that point to the mean so you want less than so you do 0.5 - that ?

Oh and you had to use the idea of the previous part of the question to work out the standard deviation/.... by wokring that the mean + 30/ standard deviation was equal to 0.5

Make sense ?
9. I was surprised there were only 6 questions the exam felt very short
10. i got 0.12 for t and 0.13 for u
11. Yeah that's what I meant sorry
12. Dropped on PMCC changing and also the change in standard deviation question, 3 dropped?

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13. (Original post by maggie43)
I struggled as well. How the hell were we supposed to do that

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Tou were supposed to calculate the scores for sarah using S(X) and for the other dude using S(1/X)
The ones where SX)>S(1/X) added up was probability of sarah winning
The ones where S(1/X)>S(X) were for the orther dude add them up to get the probability of this dude winning 😄
14. (Original post by zandneger)
1.
Can't remember part a)
b) wiggles were the response variable as they are what changes based on the distance
c) the regression line I got was 0.722+0.014d
d) I subbed in 350 and got w=5.69
my answer was reliable because it was within the range of data

2.
a) 2p+Q=0.5
b) Q=0.15 P=0.175
c) 2.2 something like that?
d) E(R) =0.45
e) Sara's chance = 0.475 Rebecca's chance = 0.375

3.I don't remember much about this question other than the PMCC being around -0.7 and the extra data causing the PMCC to increase because it showed a positive correlation.

4.
a) 0
b) t=0.03
c) u=0.22
d) 0.45 and 15/37
e) 33 customers ordered dinner

5.
a) median baby weight was 3.47
b) s.d was 0.689
c) showed mean was 3.43
d) used that guys normal distribution to get that 0.2546 babies were under 3kg
e) showed that in the table only 9 babies were under 3kg whereas using his distribution I got that 12 babies were under 3kg hence he is wrong to assume the distribution

6.
a) 6.68% of men took over 300 minutes
b) the speedy chap needed to run his marathon in under 206 minutes
c) the probability was 0.18/0.5 (0.36)
For question 6.a, i left it as the probability. Will i lose a mark for not multiplying by 100?

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15. (Original post by Dayzh)
i got 0.12 for t and 0.13 for u
Same everyone else seems to have got 0.03 and 0'22
16. Wasnt saras chance 0.65 and rebeccas 0.2???

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17. (Original post by habibtii)
how are you able to remember this all wow. en waarom heet jij zandneger.
6b) wasnt it 274 to 3sf?

P(T>x)=0.2

(x-240)/40=0.8416

x=273.664
18. (Original post by Siddhart1998)
61 for A?
I'm thinking more along the lines of 58/75 for an A
19. Nah bruh, last year's paper was harder personally
20. (Original post by zandneger)
1.
Can't remember part a)
b) wiggles were the response variable as they are what changes based on the distance
c) the regression line I got was 0.722+0.014d
d) I subbed in 350 and got w=5.69
my answer was reliable because it was within the range of data

2.
a) 2p+Q=0.5
b) Q=0.15 P=0.175
c) 2.2 something like that?
d) E(R) =0.45
e) Sara's chance = 0.475 Rebecca's chance = 0.375

3.I don't remember much about this question other than the PMCC being around -0.7 and the extra data causing the PMCC to increase because it showed a positive correlation.

4.
a) 0
b) t=0.03
c) u=0.22
d) 0.45 and 15/37
e) 33 customers ordered dinner

5.
a) median baby weight was 3.47
b) s.d was 0.689
c) showed mean was 3.43
d) used that guys normal distribution to get that 0.2546 babies were under 3kg
e) showed that in the table only 9 babies were under 3kg whereas using his distribution I got that 12 babies were under 3kg hence he is wrong to assume the distribution

6.
a) 6.68% of men took over 300 minutes
b) the speedy chap needed to run his marathon in under 206 minutes
c) the probability was 0.18/0.5 (0.36)
they all seem pretty correct, the only difference to me was that i said the guy with the normal distribution for the babies was fine to use that equation since the mean and median of the data were pretty close indicating a symmetrical distribution

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