Official Edexcel S3 thread Wednesday 20 May 2015 Morning [6691]

Original post by YuFRO

Why is the variance 4 sigma squared over 5 for question 5 d?

Take variance's, so Var(φ)=(1/25)(16σ^2+σ^2+σ^2+σ^2+σ^2)

Reply 706

YuFRO

Original post by Gome44

Take variance's, so Var(φ)=(1/25)(16σ^2+σ^2+σ^2+σ^2+σ^2)

Thanks dude, I messed that up. Idk why now, but I had it as 2 sigma^2. Method was right though, idk how many marks I'll lose for that. What do you think the A* boundary will be?

Reply 707

I feel like such a fool, I answered the "hard" questions and then managed to mess up the hypothesis test for the means, probably lost 6 marks on it :angry:

Reply 708

Grade boundaries ~ 66/75 for A* please? :frown:

Reply 709

DCMed96

16

Original post by Davothebigafro

Grade boundaries ~ 66/75 for A* please? :frown:

Doubt it.... it is gonna be high as hell

Reply 710

Original post by YuFRO

Thanks dude, I messed that up. Idk why now, but I had it as 2 sigma^2. Method was right though, idk how many marks I'll lose for that. What do you think the A* boundary will be?

I reckon 68, judging on the poll that was made on tsr

Reply 711

Original post by Gome44

I reckon 68, judging on the poll that was made on tsr

I doubt the people who post on TSR after the exam are too representative everyone who took the exam though

Reply 712

Original post by DCMed96

Doubt it.... it is gonna be high as hell

Reply 713

Original post by Davothebigafro

I doubt the people who post on TSR after the exam are too representative everyone who took the exam though

Most of them voted hard or very hard

Reply 714

http://www.thestudentroom.co.uk/showthread.php?t=3344567

Original post by Davothebigafro

I doubt the people who post on TSR after the exam are too representative everyone who took the exam though

Reply 715

http://www.thestudentroom.co.uk/showthread.php?t=3344567

Original post by Gome44

How does that = 68 then?

Reply 716

Original post by Davothebigafro

How does that = 68 then?

Only question 5d) was really tricky, 6 was a bit weird but manageable, the rest was standard stuff I thought. Lots of the time (and I am guilty of this as well), people think a paper is so much harder than last years (see current c2 thread), when really it's a fairly standard paper with 1 or 2 tricky bits, it's just exam pressure that makes it harder

Reply 717

Original post by Davothebigafro

How does that = 68 then?

And 68 is quite low for s3 I think (looking at recent years)

Reply 718