S2 MEI OCR 10th June 2014 Official Thread

Which one?

1) Find it to 3dp
2) Use linear interpolation between values in the difference table when we need to find for example (PX<0.4125)

Doesn't using a calculator rather than a reading from the normal distribution values table, give faster and more accurate values anyway?

Reply 21

Illiberal Liberal

2

Original post by Tinglay

Doesn't using a calculator rather than a reading from the normal distribution values table, give faster and more accurate values anyway?

How would you use a calculator to find P(X<0.4125) for a normal distribution? :confused:

That's the whole point of the normal tables...

Reply 22

username1186351

1

Original post by Law-Hopeful

How would you use a calculator to find P(X<0.4125) for a normal distribution? :confused:

That's the whole point of the normal tables...

I've done every normal distribution question without the table and have acquired accurate figures lol (except the inverse normal tables)

If you have a fx-911 press setup, stat and then 1 and press ON. Then press shift 1(stat) and choose 5. The relevant options are 1 and 3. If the value is p(Z<0.4125) you plug it into the first option 1 P), if it's P(Z>0.4125) you plug it into R) the third option.

It is more accurate than the tables as it gives it to more than 3dp. You are less prone to making errors since you only have to plug in numbers, not read from some yellow table in a booklet.

However, since it's only a few days before the exam I would use your method and use the calculator to check only.

(edited 9 years ago)

Reply 23

googlebotsgoogle

OP

Accuracy of the regression and residuals? Is it always to 3 significant figures?

Reply 24

visualcocaine

You know when you're doing a hypothesis test fro the sample means, is the definition of μ the population mean of the sample or the original mean? I always seem to get this wrong :confused:

Reply 25

Illiberal Liberal

2

Original post by Tinglay

I've done every normal distribution question without the table and have acquired accurate figures lol (except the inverse normal tables)

If you have a fx-911 press setup, stat and then 1 and press ON. Then press shift 1(stat) and choose 5. The relevant options are 1 and 3. If the value is p(Z<0.4125) you plug it into the first option 1 P), if it's P(Z>0.4125) you plug it into R) the third option.

It is more accurate than the tables as it gives it to more than 3dp. You are less prone to making errors since you only have to plug in numbers, not read from some yellow table in a booklet.

However, since it's only a few days before the exam I would use your method and use the calculator to check only.

I have a Sharp EL-9900 but I think I'll use my method, thanks anyway!

Original post by visualcocaine

You know when you're doing a hypothesis test fro the sample means, is the definition of μ the population mean of the sample or the original mean? I always seem to get this wrong :confused:

Of the sample.

Reply 26

visualcocaine

Original post by Law-Hopeful

I have a Sharp EL-9900 but I think I'll use my method, thanks anyway!

Of the sample.

thank you

Reply 27

Jesseo

Hopefully this doesn't spend a day getting moderated like my last post with a link, these are really useful

http://www.furthermaths.org.uk/?section=students&page=mei-revision

It covers all of the mei further maths except for S3,S4,DE and M3

Reply 28

Chowdhury96

μ= sample mean. When you're writing out your hypotheses, μ is the population (original) mean. Otherwise when you subtract the mean from your value, it'll give you 0.

Reply 29

Chowdhury96

Original post by Law-Hopeful

How do we use the Normal difference tables to find for example P(X<0.4125)? Would we find P(X<0.413) or do we find 0.0005 between 0.002 and 0.003 using the difference tables then add it on to 0.412?

Thanks :smile:

I always do it to 3dp and it gives me the right answer. If I were you, I wouldn't start messing around with interpolation, I don't think it would be accurate, given that the normal distribution graph is curved.

Reply 30

sasunerd

1

Does anyone else think that S2 just seems so much better than S1? Can't wait till tomorrow is over and done with!

Reply 31

candy963

Hi can anybody help me please? I'm doing the Jan 2013 past paper and for question 3(iv) why on the Mark scheme do they find the inverse value of 0.975 rather than 0.95?
If any one could help me I'd be very grateful thanks :smile:

Reply 32

dianaantemir

Original post by candy963

Hi can anybody help me please? I'm doing the Jan 2013 past paper and for question 3(iv) why on the Mark scheme do they find the inverse value of 0.975 rather than 0.95?
If any one could help me I'd be very grateful thanks :smile:

That usually happens when there's a two tailed test :smile:

Posted from TSR Mobile

Reply 33

candy963

Original post by dianaantemir

That usually happens when there's a two tailed test :smile:

Posted from TSR Mobile

Thank you in this case I have to find the values of and and b in P(a<Y<b)=0.95 is this a two tailed test and how would you tell?

Reply 34

Yorkmag

anyone got a mark scheme for june 2013?

Reply 35

sasunerd

1

Original post by Yorkmag

anyone got a mark scheme for june 2013?

http://www.sixthform.m34maths.com/A-level%20exams/Stats2/ms%202013%20June%20S2.pdf

Thar you go, buddy.

Reply 36

username1186351

1

Original post by Yorkmag

anyone got a mark scheme for june 2013?

--

I think every question is straightfoward except 5 mark poisson distributions questions like the butterfly question in 2013 Jan, anyone have any tips for those?

Sometimes you have to use trial and error through tables, sometimes you have to use trial and error without the table, slightly confusing for me.

Reply 38

Yorkmag

Original post by sasunerd

http://www.sixthform.m34maths.com/A-level%20exams/Stats2/ms%202013%20June%20S2.pdf

Thar you go, buddy.

Thanks for that your a lifesaver!

Reply 39

sasunerd

1

Original post by Tinglay

I think every question is straightfoward except 5 mark poisson distributions questions like the butterfly question in 2013 Jan, anyone have any tips for those?

Sometimes you have to use trial and error through tables, sometimes you have to use trial and error without the table, slightly confusing for me.

Trial and error just kicks me in the butt so I use the inverse of normal for those instead, slightly easier but honestly it took me two days to fully understand it. And a lotta questions.

S2 MEI OCR 10th June 2014 Official Thread

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