S1 June 2016 UK Model Answers (Edexcel)

Soz for the delay. Got caught up with the Euro games :colondollar:

I thought this was quite tricky
https://drive.google.com/open?id=0B3xSC6XqSy7kMGhaRHh2MHlnaDQ

EDIT: 5(e) I didn't realise it said use answer to part d too. In part d P(W<3) = 0.2546 whereas the actual P(W<3)=0.18. My comment would be that this just further consolidates that the normal model is not really accurate. Also, I don't think saying the decision to use the normal model on the basis that the median and median are close will be accepted. While the median and mean are close, the data is not nearly symmetrical, if it were part d P(W<3) would have yielded a more accurate approximation.

Coming up the June 2017 S1 for q4(d)(i) I've had some private messages asking why P(D | B) = P(D). This is because we are told that events D and B are both independent. Therefore P(D 'given' B) = P(D) since D is independent of whether B happens or not. That's what it means for two events to be independent, none of them have any bearing on the other.

(edited 6 years ago)

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Reply 1

Dohaeris

Awesome, thank you for uploading this! It'll put a lot of minds at ease

Reply 2

ombtom

Original post by kprime2

Soz for the delay. Got caught up with the Euro games :colondollar:

I thought this was quite tricky
https://drive.google.com/open?id=0B3xSC6XqSy7kMGhaRHh2MHlnaDQ

You beautiful beautiful person.

(Now do M4!)

Reply 3

TheRandomGenius

Thanks so much for this. Few questions:

1) Would rounding and hence giving E(X) to 3sf lose any marks? (you gave the full answer with decimals)

2) For 3e, what do you thin of the argument that the new x point and y point was significantly above the mean for x and y respectively and thus lay far away from the 'line of best fit' created by the PMCC. This means that the PMMC falls. 2 marks?

3) For 3-d-ii, I made a silly slip and forgot to take into account 0.15 for my denominator (and so got 15/22 rather than 15/37). Because of this, I also got the wrong answer for part e (although my method was correct, identical to yours). How many marks do you reckon I would lose for both of these errors?

4) For 4d, I again made a silly sign slip, meaning I forgot to do '1 minus'. My final answer was 0.745. 1 or 2 marks lost?

I understand if you can't answer all of the above but I would really appreciate it if you could. Thanks again for doing the solutions.

Reply 4

kprime2

Original post by ombtom

You beautiful beautiful person.

(Now do M4!)

M4 is beyond me x_x

Reply 5

cogito.

I can do M4 if I have the access to questions.

Original post by ombtom

You beautiful beautiful person.

(Now do M4!)

Reply 6

DaVinciGirl

Thank you!

Posted from TSR Mobile

Reply 7

Tigernoob

Do u know how to get IAL S1s model answers?

Reply 8

leestitt

Original post by kprime2

Soz for the delay. Got caught up with the Euro games :colondollar:

I thought this was quite tricky
https://drive.google.com/open?id=0B3xSC6XqSy7kMGhaRHh2MHlnaDQ

I got 61 marks i think, does anyone know if this is a B or a C?

Reply 9

LukeB98

Original post by leestitt

I got 61 marks i think, does anyone know if this is a B or a C?

More likely to be an A.

Reply 10

leestitt

Original post by LukeB98

More likely to be an A.

Oh really?!

Reply 11

TonyDaniels357

for question 6b i got my z value as just -0.84 so it is basically rounded , would i still get full marks as my T value came out as 206.4 it should fit the range the mark scheme has?

Reply 12

TonyDaniels357

Original post by kprime2

Soz for the delay. Got caught up with the Euro games :colondollar:

I thought this was quite tricky
https://drive.google.com/open?id=0B3xSC6XqSy7kMGhaRHh2MHlnaDQ

for question 6b i got my z value as just -0.84 so it is basically rounded , would i still get full marks as my T value came out as 206.4 it should fit the range the mark scheme has?

Reply 13

kprime2

Original post by TonyDaniels357

for question 6b i got my z value as just -0.84 so it is basically rounded , would i still get full marks as my T value came out as 206.4 it should fit the range the mark scheme has?

Mark scheme will probably say AWRT to 206.

*AWRT - answers which round to

Reply 14

kprime2

Original post by TheRandomGenius

Nah

No. Sxy was negative and it now increases, and Sxx and Syy becomes bigger. Therefore the correlation is 'less negative' ie increases

No idea

No idea

(edited 7 years ago)

Reply 15

TonyDaniels357