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# AQA S1 , No working out needed ?

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1. do you have to show working out in statistics 1 (S1) ?
because you can do everything in the graphical calculator
2. Yes. Most questions have several method marks that you'd miss if you were to skip to the answers immediately.
3. (Original post by Asuna Yuuki)
Yes. Most questions have several method marks that you'd miss if you were to skip to the answers immediately.
for example ?
4. Based on the past papers I have done (only a few) you don't need to show working out for most things?
For example product moment correlation coefficient doesn't require any working out.
If you get the right answer then you get all the marks.

I'd suggest looking through past papers and look at the mark schemes. I'm not quite sure.
Obviously showing working out for normal distribution stuff & probability.
For line of regression I just get my a & b from the calculator.
I also get means and sd from my calculator.
5. Questions where x bar squared or sxx are given in sd or pmcc calculations respectively must have shown working out. As a rule, i would always show working out where possible unless you are out of time or have checked answer thoroughly.
6. (Original post by Pentaquark)
Based on the past papers I have done (only a few) you don't need to show working out for most things?
For example product moment correlation coefficient doesn't require any working out.
If you get the right answer then you get all the marks.

I'd suggest looking through past papers and look at the mark schemes. I'm not quite sure.
Obviously showing working out for normal distribution stuff & probability.
For line of regression I just get my a & b from the calculator.
I also get means and sd from my calculator.
you can work out normal distributions using your calculator, so you dont need to show working out ?
7. You have to show your standardising.
8. (Original post by money-for-all)
you can work out normal distributions using your calculator, so you dont need to show working out ?
I don't have a graphical calculator.

The mark schemes I have seen require only working out
like P(X < 1.9) = P(Z<(1.9-1.81)/0.08) for M1
and P(X > 1.85) = P(Z > 0.5) = 1 – P(Z < 0.5)

Another example is
P(1.81 < X < 1.85)= (0.691 to 0.692) – 0.5 for M1
9. (Original post by inb4after)
You have to show your standardising.
how would you show that ?

would you just say mean=0 and standard deviation=1 ?

thanks
10. As mentioned above, you can get full marks for things like the correlation coefficient and the least squares regression line with no working. The flipside of this is that if you have the wrong answer (easy to do, anyone can key in an incorrect value), then you get nothing. It's always a good idea to show some working - at the very least, you should do the calculation twice, entering all of the data again, to make sure that you get the same answer.

From the most recent S1 mark scheme;

No Method Shown

Where the question specifically requires a particular method to be used, we must usually see evidence of use of this method for any marks to be awarded.

Where the answer can be reasonably obtained without showing working and it is very unlikely that the correct answer can be obtained by using an incorrect method, we must award full marks. However, the obvious penalty to candidates showing no working is that incorrect answers, however close, earn no marks.

Where a question asks the candidate to state or write down a result, no method need be shown for full marks.

Where the permitted calculator has functions which reasonably allow the solution of the question directly, the correct answer without working earns full marks, unless it is given to less than the degree of accuracy accepted in the mark scheme, when it gains no marks.

Otherwise we require evidence of a correct method for any marks to be awarded.
11. Using the formula, z = (x - mean)/standard deviation.

The examiner is looking for rearranging of this formula depending on the type of normal distribution question. You won't get any method marks by just quoting a z value out of nowhere, even if you got it from your graphical calculator.
12. (Original post by Pangol)
As mentioned above, you can get full marks for things like the correlation coefficient and the least squares regression line with no working. The flipside of this is that if you have the wrong answer (easy to do, anyone can key in an incorrect value), then you get nothing. It's always a good idea to show some working - at the very least, you should do the calculation twice, entering all of the data again, to make sure that you get the same answer.

From the most recent S1 mark scheme;

No Method Shown

Where the question specifically requires a particular method to be used, we must usually see evidence of use of this method for any marks to be awarded.

Where the answer can be reasonably obtained without showing working and it is very unlikely that the correct answer can be obtained by using an incorrect method, we must award full marks. However, the obvious penalty to candidates showing no working is that incorrect answers, however close, earn no marks.

Where a question asks the candidate to state or write down a result, no method need be shown for full marks.

Where the permitted calculator has functions which reasonably allow the solution of the question directly, the correct answer without working earns full marks, unless it is given to less than the degree of accuracy accepted in the mark scheme, when it gains no marks.

Otherwise we require evidence of a correct method for any marks to be awarded.
could you please explain this ?

thanks, will appreciate this
13. (Original post by money-for-all)
could you please explain this ?

thanks, will appreciate this
Not really sure what you want me to explain! It's a direct quote from the most recent S1 mark scheme, and seems pretty clear to me. What in particular do you want clarifying?
14. (Original post by Pangol)
Not really sure what you want me to explain! It's a direct quote from the most recent S1 mark scheme, and seems pretty clear to me. What in particular do you want clarifying?
does this mean you dont have to show working then ? as long as you got the right answer?
15. (Original post by money-for-all)
does this mean you dont have to show working then ? as long as you got the right answer?
For most questions, it would seem if you get the correct answer, then you get the marks. If you get the answer wrong though you get no marks. I'd advise you show working to get method marks in case the answer is wrong.
16. (Original post by money-for-all)
does this mean you dont have to show working then ? as long as you got the right answer?
I would suggest that you do a past paper and look at the mark scheme, and you will see that marks are awarded for things other than the correct answer.
17. Hello everyone, hope everyone's revision is going well!

One question... has anyone compiled a list of all the answers that regularly come up? For example, "Give a numerical justification as to why [a variable] is unlikely to be normally distributed" which is always calculating 2<X<4 standard deviation's from the mean. Some questions just have the same answers every time! If there is a list out there... somewhere... We could revise this list and gain the maximum marks possible

Please and thank you for any help on this x
18. For the probability questions, would you drop marks for not writing the full notation?

For example, if I wrote:
p = 0.7 * 0.5 * 0.3
P(AnBnC' ) = P(A)P(B)P(C' )

Is it acceptable to just skip straight to the probability values?

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