Edexcel Statistics S1 Exam Jan 2008

Scroll to see replies

For the question where you had to find the lower quartile, upper quartile and median.
Were were supposed to find it out using:

Q_1 = \frac{n + 1}{4}

Q_2 = \frac{n + 1}{2}

Q_3 = \frac{3(n + 1)}{4}

I remember

Q_3

being 258,

Q_1

being 171 and

Q_2

being 210. Did anyone else get that?

Reply 61

Alessandro_22

ye thats what i got at first but thats coz i typed it into the calculator wrong lol

Reply 62

M.A.H

TaChYcArDiA

yeah whoever posted those E(T) and Var(T) values...I got the same as you whooop!!! That means we got the whole last question correct - whoooop!!!

Hey erm...what did you guys get for the probability of the complaint for the pop-corn question??? It was really low but I think it was right but I need to know if anyone got the same answer as me...I can't remember the answer...

oh and for one of the first few questions did you guys get a positive skew for that thing where you had to evaluate the given formula...

and what method did u lot use to find Q2 ...did you use (n+1)/2 and that gave 6.5th itm and so i averaged 6th and 7th... or simply n/2 and copy the Q2 value...

yeh

Reply 63

Ariana123

and what method did u lot use to find Q2 ...did you use (n+1)/2 and that gave 6.5th itm and so i averaged 6th and 7th... or simply n/2 and copy the Q2 value...

i never averaged the 6th and 7th i just took the 7th value.......... :eek:

oops

Reply 64

Ar5enal Fan

M.A.H

i got -5.88 :redface:

, we're talking about the Quartiles Q right with the smokers?

Coz i got 0.155 for Q1 part b/c which is the pmcc

Lol, was there another question where there was weak correlation? I think I might be talking about question 1 lol

Reply 65

M.A.H

gj3

ye thats what i got at first but thats coz i typed it into the calculator wrong lol

the -5.88? :s-smilie:

Reply 66

M.A.H

Ar5enal Fan

Lol, was there another question where there was weak correlation? I think I might be talking about question 1 lol

nope only 1

Reply 67

Ariana123

eugh i'm really annoyed i never ordered that data. ok i never got a good grade in stats then, heres hoping my C2 and C1 brings it up.

Reply 68

Ar5enal Fan

M.A.H

nope only 1

No I think there was a question about a training program and then the results after one year and you had to evaluate whether or not there had been successful results and as I got a weak correlation I said that it hadn't been a success for the first year.

Reply 69

Ribulose Bisphosphate

Fairy_Pop

and what method did u lot use to find Q2 ...did you use (n+1)/2 and that gave 6.5th itm and so i averaged 6th and 7th... or simply n/2 and copy the Q2 value...

i never averaged the 6th and 7th i just took the 7th value.......... :eek:

oops

yeah i wasn't sure whether i had to round up the 6.5 to 7th item and simply read it off (which is what i initially done)...or average the 6th and 7th values (which is what i done in the end)...

but for Q1 and Q3 i simply done 0.25 x 12 and 0.75 x 12 and i read off the 3rd and 9th values...

does anybody know?

Reply 70

Alessandro_22

i dont understand for the histogram if you got 12 as your final answer then frequency density was 1.2, didnt look anywhere near over one on the graph or was the graph not accurate?

Reply 71

M.A.H

Ar5enal Fan

yeh for that the pmcc was 0.155 (what i got) i dont think there was another question asking to work out the pmcc

Reply 72

Ribulose Bisphosphate

the frequency density for the last bar was 0.5 or something...

Reply 73

edward_wells90

For the last bit of Q1, about it being a guide. Something about admissions test...

Did people work out r = 0.016

then we had to compare it with the one they gave us r=-0.015, and say whether it was a guide or not..
I wrote the r value is the same (excluding the positive and negative) so theres not much of a correlation and its not so good for comparing sets of data.

What did people write?

edit: I can't remember the exact values of r but they were something like those i used^^

Reply 74

M.A.H

TaChYcArDiA

i never averaged the 6th and 7th i just took the 7th value.......... :eek:

oops

yeah i wasn't sure whether i had to round up the 6.5 to 7th item and simply read it off (which is what i initially done)...or average the 6th and 7th values (which is what i done in the end)...

but for Q1 and Q3 i simply done 0.25 x 12 and 0.75 x 12 and i read off the 3rd and 9th values...

does anybody know?
i remember my teacher saying if n is even we can just take the 3rd term or watever, if n is odd then we take the average

Reply 75

Ariana123

the pmcc questions were gooood. good old formula booklets :wink:

Reply 76

Ar5enal Fan

M.A.H

yeh for that the pmcc was 0.155 (what i got) i dont think there was another question asking to work out the pmcc

Yh, I think i got 0.155 as well

Reply 77

Ariana123

edward_wells90

yeah i got something like that for r. don't remember the rest of that question.

Reply 78

Ribulose Bisphosphate

edward_wells90

i never liked that explanation...usually the explanations are easier to write about but they went and introduced a third variable for the discussion which confused me a bit...i wrote bare rubbish for that bit