A level Statistics doubt??Post your doubts here!

[Rabb94]

i believe it's just been answered here:
https://www.xtremepapers.com/community/threads/mathematics-post-your-doubts-here.9599/page-482

jazakallah khair

 

[Rabb94]

hi
could someone solve ques 6iii

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s12_qp_63.pdf

 

[Rabb94]

hi
could someone solve ques 6ii
http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_s12_qp_61.pdf

 

[Alice123]

http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_s11_qp_63.pdf
4 ii part. littlecloud11 Jiyad Ahsan syed1995
how do i get P(C)??? isnt it supposed to be 3/6?

 

[MyraMylo]

when do we use 6.5 incase of fewer/ lesser than 7 and when do we use 7?
I am really confused about this

 

[Ryan123]

http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_s11_qp_63.pdf
4 ii part. littlecloud11 Jiyad Ahsan syed1995
how do i get P(C)??? isnt it supposed to be 3/6?

Well P(C) is product is even so if you list out the possibilities which are (12 14 16 21 22 23 24 25 26 32 34 36 41 42 43 44 45 46 52 54 56 61 62 63 64 65 66)
so its 27/36= 3/4

 

[littlecloud11]

http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_s11_qp_63.pdf
4 ii part. littlecloud11 Jiyad Ahsan syed1995
how do i get P(C)??? isnt it supposed to be 3/6?

The possible combos for P(C) = (1,2) (1,4) (1,6) (2,2) (2,3) (2,4) (2,5) (2,6) (3,4) (3,6) (4,4) (4,5) (4,6) (5,6) and (6,6) = that's 27 in total.
So P(C)= 27/36 = 3/4

 

[littlecloud11]

when do we use 6.5 incase of fewer/ lesser than 7 and when do we use 7?
I am really confused about this

You use continuity correction when you use a continuous function to approximate a discreet one. Like when you use normal distribution to estimate a binomial. Example, In a sample of X data find the probability that < than 20 will have 51 feathers.

 

[A star]

You use continuity correction when you use a continuous function to approximate a discreet one. Like when you normal distribution to estimate a binomial. Example, In a sample of X data find the probability that < than 20 will have 51 feathers.

so that what its called i called it continuety correctivity
thats y my sir said it was wrong

 

[SexyFag]

http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_s12_qp_62.pdf

QUestion 2 anyone?

 

[littlecloud11]

so that what its called i called it continuety correctivity
thats y my sir said it was wrong

Close enough.

 

[Ryan123]

http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_s12_qp_62.pdf

QUestion 2 anyone?

Y is 0 if same or greater minus the smaller value of x there Y can only be 0(22 44 66) 2(24 42 46 64) 4(26 62) so for 0 its (.5*.5+.4*.4+.1*.1) for 2 its (.5*.4)*2+(.1*.4)*2 and for 4 its (.5*.1)*2
Y=0 2 4
p y=.42 .48 .1(respectively)
ex = .96.4=1.36

 

[A star]

http://papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Mathematics%20(9709)/9709_s12_qp_63.pdf
2 part ii i get the working but my answer is coming 163.6 instead :/

 

[littlecloud11]

http://papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Mathematics%20(9709)/9709_s12_qp_63.pdf
2 part ii i get the working but my answer is coming 163.6 instead :/

Did you get the standard deviation as 3.2? If you did then it's just (3.2)^2 * 15 which is 153.6

 

[Ryan123]

Did you get the standard deviation as 3.2? If you did then it's just (3.2)^2 * 15 which is 153.6

how do you find the s.d?
i got the ans but i did it in a much longer way...found the sum of xsquare first and then from there on got the rest
and also http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_s12_qp_61.pdf
how to get the sd in 5iii
thanks for any help

 

[A star]

Did you get the standard deviation as 3.2? If you did then it's just (3.2)^2 * 15 which is 153.6

got it was a silly serror didnt realise sum(x-104.8)=0 -_-

 

[MyraMylo]

You use continuity correction when you use a continuous function to approximate a discreet one. Like when you use normal distribution to estimate a binomial. Example, In a sample of X data find the probability that < than 20 will have 51 feathers.

but how do i tell the difference between such type of questions...i have seen many problems where we are supposed to find the probability of fewer than 75(for e.g.) and we use (75-mean)/S.D. to calculate it...
my teacher told me that whenever we have to add or subtract 0.5...we are told to use normal approximation in the question...but this is not always the case...

 

[A star]

but how do i tell the difference between such type of questions...i have seen many problems where we are supposed to find the probability of fewer than 75(for e.g.) and we use (75-mean)/S.D. to calculate it...
my teacher told me that whenever we have to add or subtract 0.5...we are told to use normal approximation in the question...but this is not always the case...

cc is only applied where there is a conversion from binomial to normal

 

[MyraMylo]

cc is only applied where there is a conversion from binomial to normal

Thanks a ton...could you plz elaborate what you mean by conversion from binomial to normal...i am sorry i can do questions just fine but i don't really get what is meant by binomial, normal etc...can yu plz just give me an example question...i ll be very thankful..

 

[littlecloud11]

how do you find the s.d?
i got the ans but i did it in a much longer way...found the sum of xsquare first and then from there on got the rest
and also http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s12_qp_61.pdf
how to get the sd in 5iii
thanks for any help

2ii) for sd.=√ S(x − 100)^2/15 - (72/15)^2
=√10.24 = 3.2

Summer 12/61
mean is 8.34/9
for sd.= √ [(.76)^2 +(.85)^2+(.89)^2+(.91)^2+(.92)^2+(.94)^2+(.96)^2+(1.04)^2+(1.07)^2]/9 - (8.34/9)^2
=√(7.7984/9) - (8.34/9)^2 = .0882