For Q3b)

If you compare the formulae for Variance and Syy, you'll notice that Syy = n x Var(Y), which makes it a lot easier!
I got the same answer tho.

Interesting. I haven't touched S1 for three years excuse my memory

Reply 44

kprime2

Original post by kawaii289

guesses on what 70/75 will be in ums ? I need 90+ !

98-100 ums

Reply 45

kprime2

Original post by vignesh1234567

When you said the PMCC value r increases, did you mean that it goes closer to 0 or does it get closer to -1?

I meant it increases so it gets closer to 0. Getting closer to -1 means it's decreasing.

Reply 46

kprime2

Original post by Ayman!

Actually looks like an interesting S1 paper.

What are your views on it? I thought 2(f), 3(e), 4(d)(e), 5(e)(f) were especially tricky and will be answered poorly.

The venn inside a venn on question 4 was highly unusual, it would have thrown a lot of students off in exam conditions.

Reply 47

fowlerj

Original post by Hasanalm

Hey mate could you just answer some questions please.
For question 3a, I wrote sum of x squared as 958.88 as opposed to the actual 985.88, then carried on with the calculation as so. Will I lose all 3 marks for this error or will I get some marks?

For 4b, I wrote independent so P(B AND D)= P(B) x P(D). Will this get me one mark?

For 4di and 4dii, will I get any marks for writing out the formula , so for I 4di wrote that is is equal to P(D AND R AND B) divided by P(R AND B) and for 4dii I wrote that it is equal to P(D AND R AND NOT B) divided by P(R AND NOT B). Will I get any marks for laying these formulas out?

For question 5a, I got the width right but height wrong. Will this only get me 1/3 marks?

For 5e I said that it may be a good decision as the median and mean are quite similar, will this get me any marks?

Thanks mate<3

You should get some method marks for 3a.
Nothing for Q4 (just formulae) unless you used some numbers (even if incorrect ones)
5a should get 1 mark
5e that's what I put - they often allow a couple of variations.
Wasn't sure how to include P(X<3) in the explanation

Reply 48

imran_

C1 69/75
C2 67/75
S1 52-55/75

would this be an A

Reply 49

Ayman!

Original post by kprime2

2(f) feels sort of like some proper probability and 4 just looks horrible in general :lol:

Last bits of 5 needed some intuitive understanding. 6 probably would be tricky to do for a few as well.

Overall, I like the paper. :tongue:

Reply 50

username963570

Fellas, what do we feel 62-63/75 is gonna be, UMS wise? Should be a comfortable A, but we thinking 84-85 UMS? Normally that would be around 81-82 UMS but given this paper was trickier than most, we thinking an A boundary falling to 57/58 ?

Reply 51

Bassam98

Will you be doing the m2 ial paper?

Reply 52

Nathan000

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

Will yoube doing one for D1 ?

Reply 53

username963570

Original post by Ayman!

2(f) feels sort of like some proper probability and 4 just looks horrible in general :lol:

Last bits of 5 needed some intuitive understanding. 6 probably would be tricky to do for a few as well.

Overall, I like the paper. :tongue:

First 6 marks of Q6 are standard, but the last 3 will prove difficult for a majority. Q4 is a nasty probability Q, agreed.

Reply 54

GarlicBread01

For question 3(d) I got r=-0.753 instead of r=-0.754, this was because I used the exact value of Syy (with the decimals) instead of the given value of Syy (without the decimals).

Will this lose any marks?

Reply 55

kprime2

Original post by GarlicBread01

Nah

Reply 56

Rafeerahman

in the skewness question, did anyone write that the mean (3.43) was close to the median ( 3.47) so normal distribution can be used. i wanted to do the 3 (mean-median)/sd calculation but later i didnt do that uggghhhhh. i also wrote that the standard deviation he used (0.65) was a bit deviated from the standard deviation we had to find (0.68). i said despite these small inaccuracies, a normal distribution was fairly appropriate. am i getting 0 out of 3 for this?

Reply 57

Rafeerahman

Original post by Rafeerahman

Also I have another question ( sorry this is not related to s1 but its a quick question) I heard that in m1 we only lose one mark for wrong significant figures in m1, is this true. cause a lot of people including me wrote 16.63 N, 11.76 N, 15.54 N for example.... I even asked my teacher a few days before the exam and he said to leave answers to 2 decimal places.