AQA M1SB 8th of june 2016 unofficial markscheme

Do we need above 95% in each maths module to study maths in oxford???

My answers (no idea if they are right ir not just contributing):

1.)a.) r=0.9591...
b.) Strong correlation blah blah

2.)a.)i.) 26
ii.) Median: 25, IQR: 2
b.) Mean and range
c.) Mean: 25.6, Range: 45

3.)a.)i.) 0.352
ii.) 0.136
iii.) 0.158
iv.) 0.792
v.) 0.267
b.) 0.00513

4.)a.) y= 181.3 + 3.0042x
b.) (context of gradient)
c.) 385
d.) I put the estimate was accurate as even though the residuals are large so are the values of Y but this could well be wrong.

5.)a.)i.) 0.941
ii.) 0.149
iii.) 0.792
iv.) Unity
b.) 1522.7
c.)i.) 0.355
ii.) 0.993

6.)a.)i.) 0.0262
ii.) 0.880
iii.) 0.101
iv.) 0.891
b.) Mean: 54, Var: 44.28

7.)a.) (257.92,377.08)
b.)i.) 381 not equal to 400 so not valid
ii.) 7/40 not equal to 0.25 so not valid (which is wrong, it IS valid but i didnt read the question properly)

Hope this helps, please point out if I went wrong somewhere which I'm sure i did in multiple places.

how did you get 0.00513 in question 3b? I think I did the same but why others get 0.0308?

it wasn't the first 10, as otherwise you would be comparing pounds to euros. You had to either convert the euros to pounds, or the pounds to euros and then find that it was 7/40 entries.

Im sure the table were all in euros and the answer had to be in euros? There was no mention of pounds... So no conversion required? Did i read the question wrong

For question 3b I thought, to account for different combination you had to multiply by 4! (24) because there where four conditions to be met, so the amount of times they could be ordered is 4!? or are A(1) A(2) B(1) B(2) and A(2) A(1) B(1) B(2) considered to be the same and so you don't have to include both their probabilities, etc.?

I think you may have misread it :/ the table was definitely in £ and it told you the conversion was £1 to 1.2 euros. It was trying to see whether you would multiply the mean and SD they gave you when they wanted answers in Euros.

Oh crap! REALLY
Im such an idiot urgh. Thanks for the correction though You probably got it right then!

It's 4!/2!*2!, 2!*2! because there are two unique events and they both occur twice.I had to verify it in the exam by drawing a probability tree to check I had all the combinations covered.

It's 4!/2!*2!, 2!*2! because there are two unique events and they both occur twice.

I had to verify it in the exam by drawing a probability tree to check I had all the combinations covered.

Okay i didnt do that... I did (condition A)^2 + (condition B)^2. Then i subtracted this from 1... Because these four people were not part of the population of 500.

Now I realise that I shouldn't have added the two probablilities
Does that make sense or is that completely wrong?

If I am understanding what I DID wrong, then I think you should have multiplied where you added because you are finding the probability of independent event occurring, and then multiplied all of that by 6 to account for the different orders the people could be picked out.

i thought it was the first 10 that bought less than 200
=> 10/40 = 25%

I'm not sure if you were supposed to square the probability because it wasn't from the sample they gave you or it was dependent and you had to decrease the denominator. I did 6* 164/500*163/499*121/498*120/497 or something similar, can't remember the exact numbers but now I'm doubting whether that was correct.

The values on the table were the amounts they paid in pounds. It asked if less than 25% of people bought fewer than 200 euros. This means only the first 7 would have bought fewer than 200 euros because you had to times it by 1.2.

7/40 x 100 = 17.5%

At least that's what I put, not sure.

My answers (no idea if they are right ir not just contributing):

1.)a.) r=0.9591...
b.) Strong correlation blah blah

2.)a.)i.) 26
ii.) Median: 25, IQR: 2
b.) Mean and range
c.) Mean: 25.6, Range: 45

3.)a.)i.) 0.352
ii.) 0.136
iii.) 0.158
iv.) 0.792
v.) 0.267
b.) 0.00513

4.)a.) y= 181.3 + 3.0042x
b.) (context of gradient)
c.) 385
d.) I put the estimate was accurate as even though the residuals are large so are the values of Y but this could well be wrong.

5.)a.)i.) 0.941
ii.) 0.149
iii.) 0.792
iv.) Unity
b.) 1522.7
c.)i.) 0.355
ii.) 0.993

6.)a.)i.) 0.0262
ii.) 0.880
iii.) 0.101
iv.) 0.891
b.) Mean: 54, Var: 44.28

7.)a.) (257.92,377.08)
b.)i.) 381 not equal to 400 so not valid
ii.) 7/40 not equal to 0.25 so not valid (which is wrong, it IS valid but i didnt read the question properly)

Hope this helps, please point out if I went wrong somewhere which I'm sure i did in multiple places.

The values on the table were the amounts they paid in pounds. It asked if less than 25% of people bought fewer than 200 euros. This means only the first 7 would have bought fewer than 200 euros because you had to times it by 1.2.

7/40 x 100 = 17.5%

At least that's what I put, not sure.