Stats 1 Preparation

[ahmed t]

never mind
some boards do it this way like edexcel and others
but in cambrige we take the half which would be 45

 

[lotto]

thanks man!!!

 

[m2rulz143]

Guys please tell me wht are the values of

Mean+s.d
Mean+2s.d
Mean+3s.d

 

[ahmed t]

wat are u taking about??

 

[remz]

wat are u taking about??

I think he means Normal distribution probabilities.
Its 68% - 95 % - 99.9% regarding mean + 1.S.D, Mean +2 S.D, Mean + 3 S.D respectively

 

[m2rulz143]

In normal distribution they sometimes ask us probability of mean+s.d and others mentioned above directly without giving any values..

 

[ahmed t]

well then that totally depends on the question

 

[remz]

In normal distribution they sometimes ask us probability of mean+s.d and others mentioned above directly without giving any values..

Interquartile its is 0.75 (75%)
while for others i have already listed
Remember the 68-95-99.99% rule

 

[m2rulz143]

wat are u taking about??

I think he means Normal distribution probabilities.
Its 68% - 95 % - 99.9% regarding mean + 1.S.D, Mean +2 S.D, Mean + 3 S.D respectively

So for mean+s.d = 0.68
mean+2s.d = 0.95
Mean +3s.d =0.99 thanks ..

 

[remz]

wat are u taking about??

I think he means Normal distribution probabilities.
Its 68% - 95 % - 99.9% regarding mean + 1.S.D, Mean +2 S.D, Mean + 3 S.D respectively

So for mean+s.d = 0.68
mean+2s.d = 0.95
Mean +3s.d =0.99 thanks ..

yup!

 

[crash250]

i didnt get u remz about the 68-95-99.99

 

[ahmed t]

so dont i
if u use the table in the data booklet and find it out they are not the same

 

[MaXiiMo]

Guys question 3 M/J/10 (http://www.xtremepapers.me/CIE/Internat ... _qp_61.pdf)

Anyone care help me? I looked at the markscheme and I don't get it :/ (http://www.xtremepapers.me/CIE/Internat ... _ms_61.pdf)

How did they obtain the "z-values"? Please somebody help. I'm so lost. This is new to me. I have to learn all this in a few hours. Who knows it might help me make a B LOL.

 

[zwitterion7]

In normal distribution they sometimes ask us probability of mean+s.d and others mentioned above directly without giving any values..

Interquartile its is 0.75 (75%)
while for others i have already listed
Remember the 68-95-99.99% rule

What is this 68-95-99.99%???

 

[remz]

In normal distribution they sometimes ask us probability of mean+s.d and others mentioned above directly without giving any values..

Interquartile its is 0.75 (75%)
while for others i have already listed
Remember the 68-95-99.99% rule

What is this 68-95-99.99%???

Its like within one standard deviation, 68% of the values are within this range or 0.68. Within two standard deviations, its 95% of the date (values) or 0.95 and then within three SD its 99.99% or 0.99

 

[zwitterion7]

For those who are still lost and confused with stats, open the solved papers and do them. It would really be a huge help at this point and basically the only thing which you can do, because trying to do a paper with no concepts at all is pretty useless. More helpful would be if you look at the solutions and memorize them because personally i feel all the questions are alike once you get hang of the method, its pretty much similar for all.

 

[zwitterion7]

Thankyou. hey can you explain a question?

 

[zwitterion7]

http://www.xtremepapers.me/CIE/Internat ... _qp_61.pdf

Q5. Please explain.

 

[ammadanwarbaig]

Mutually exclusive and independent?
Whats the difference?

 

[zwitterion7]

Two events are mutually exclusive if:
P(A and B) = 0

For two independent events:
P(A and B)=P(A) X P(B)