Year 12s: what will be the first way you research your future options? >>

AQA A2 Maths 2017 - MS2B Statistics 2 - Tuesday 20 June [Official Thread]

Scroll to see replies

Reply 60

Zentox

I couldn't do Q7 at all :frown:

Found the paper hard

Reply 61

Diggerb

Original post by LaurenLovesMaths

I recognise lots of these but I think the very last one (and third to last) should be a^2 since the powers of 7 and 5 cancel when you put k in?

yeah, I also got Var(Y)=a^2!!!

Reply 62

Cocosweet53

Can anyone explain to me how you get k for question 7? I don't think I got I right.

Reply 63

Eddy253

Who got 9 for the last variance question?

Reply 64

67705151

Original post by LaurenLovesMaths

I recognise lots of these but I think the very last one (and third to last) should be a^2 since the powers of 7 and 5 cancel when you put k in?

Sighhh. Just realised because of my bad handwriting it did the last few questions with k as 15a^2 /16 rather than the a^2 at the bottom. Theres my 90 UMS gone and most likely my A* too. S2 boundaries are always so high

K=1/2

Original post by 67705151

Not sure if these are right but these are just some values I got, if anyone agrees or disagrees feel free to say.
7.5
6
1.73
(-4.6,75.8)
0.0992
0.4704
0.00218
0.56
6.43
1.29
0.0357
0.515
3.89
(15/(16a^5))
(1/(7a^7))
Mean is 0
Variance 7/a^7

Most likely all wrong but anyone agrees to any please say :frown:

I got your E(x) for the last question and I think maybe E(X)^2 as well but I got two terms for var(x) I think. The first term was nice like 7 but I got a horrible fraction for the second term for squaring E(x)

Posted from TSR Mobile

Reply 67

Justforquestion

guys i wrote 15/16 and then crossed it out, because i just felt it was wrong and i had a bunch of answers all over the place. Assuming that 15/16 is right, do you think i can still get most marks, because i didnt underline a final answer but i did write k=1/2 etc

Reply 68

yelash

Original post by Eddy253

K=1/2

I wasn't sure of this in the exam, but apparently answers should have been left in terms of a. Thankfully I didn't try to guess a k value, but I found the wording 'value' suggested a numerical value should be found :/

Posted from TSR Mobile

Reply 69

Cocosweet53

Original post by Zentox

I couldn't do Q7 at all :frown:

Found the paper hard

Yeah, I got to part two and was like, what?? I did manage to get the e(x) but that's because I used my graphics calculator.

Reply 70

67705151

How many marks do you guys think I'll have lost for doing my working out with an incorrect K having worked out a correct value originally? Were there any method marks available? How many marks were the last few questions work

Reply 71

Eddy253

Original post by 67705151

Yesssss

Yes but numerical value was 1/2 I swear

Reply 72

Mattyf1234

Did anyone accept Ho for their hypothesis test?

Reply 73

A*my

A*- 62 A- 54 in June 2011 which was the hardest until today. Grade boundary predictions?

Reply 74

Myachii

Predicted boundaries pls someone

Reply 75

Aimslouise

Please tell me that other people thought it was so hard? 😭

Reply 76

67705151

although it was hard it was doable and I don't think it was as difficult as some previous ones. The last question was the hardest and only so because there weren't numerical values. I think it will be something like 72 100UMS, 68 90UMS, 62 80UMS

Reply 77

yelash

Original post by Aimslouise

Please tell me that other people thought it was so hard? 😭

Yes but some parts were easier than normal, and var(X)= E(X^2)-, etc came up 3 times so you were screwed if you didn't know that XD

Posted from TSR Mobile

Reply 78

Myachii

AQA f*cked up hard. Why the hell would you say value when you want k in terms of a. Threw me off the right path completely and im sure it did for others too