Mathematics: Post your doubts here!

Rutzaba

Rutzaba

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syed1995 said:
Didn't you give the papers a long time ago ? :p

u=4s
P(X>5)=0.15
(z>(5-4s/s))=0.15
1-Phi(5-4s/s) = 0.15
Phi(5-4s/s)=0.85
5-4s/s=invPhi(0.85)

now derive the value of s.. and mean = 4*s
Click to expand...
yeah i was helping sum one and i got it and i del the post xD
 
Rutzaba

Rutzaba

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syed1995 said:
Didn't you give the papers a long time ago ? :p

u=4s
P(X>5)=0.15
(z>(5-4s/s))=0.15
1-Phi(5-4s/s) = 0.15
Phi(5-4s/s)=0.85
5-4s/s=invPhi(0.85)

now derive the value of s.. and mean = 4*s
Click to expand...
listen can you do 5 part three of the same year?please
 
railey

railey

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Salaam Alaykum, Please help:
Esme noted the test mark, x, of 16 people in a class, she found that Σ x= 824 and that the standard deviation of x was 6.5
i) Calculate Σ (x-50) and Σ (x-50)²
ii) One person did the test earlier and her mark was 72. Calculate her new mean and standard deviation of the marks of all 17 people.


Thanks in advance Ali Railey​
 
Esme

Esme

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railey said:
Salaam Alaykum, Please help:​
Esme noted the test mark, x, of 16 people in a class, she found that Σ x= 824 and that the standard deviation of x was 6.5​
i) Calculate Σ (x-50) and Σ (x-50)²​
ii) One person did the test earlier and her mark was 72. Calculate her new mean and standard deviation of the marks of all 17 people. ​
​
​
Thanks in advance Ali Railey​
Click to expand...

"Esme" :p :D

Sorry for the useless post...
 
R

Ryan123

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iFuz said:
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_w09_qp_62.pdf
Question 7 part (ii) Please?

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_w11_qp_62.pdf
Question 3 part (ii) ?
Greengage one's?
Click to expand...
abt the Greengage one not 100% sure but its like this
*R*E*E*N(GG)A*E* if you consider both g's as 1 then there is 7 letters and the starts as places where the g's can be then there are 7 slots since in one slot the 3rd g will be placed in the other gg's got 6 slots so its 7!*6/3!(for the eees)
 
iFuz

iFuz

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Ryan123 said:
abt the Greengage one not 100% sure but its like this
*R*E*E*N(GG)A*E* if you consider both g's as 1 then there is 7 letters and the starts as places where the g's can be then there are 7 slots since in one slot the 3rd g will be placed in the other gg's got 6 slots so its 7!*6/3!(for the eees)
Click to expand...
But what about other G ? :eek:

And other question?
 
iFuz

iFuz

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When do we take values of
eg.

P(X < k) = 0.7465

When will we take

phi(k) = 0.7465

and how will we know that if its correct of we should use.

1 - phi(k) = 0.7465
 
M

m.adam

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iFuz said:
When do we take values of
eg.

P(X < k) = 0.7465

When will we take

phi(k) = 0.7465

and how will we know that if its correct of we should use.

1 - phi(k) = 0.7465
Click to expand...


assalam walaikum
brother... if it is phi(-k)=0.7465
according to the rule phi(-k)= 1- phi(k)
hope that helps
 
daviruss

daviruss

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railey said:
Salaam Alaykum, Please help:​
Esme noted the test mark, x, of 16 people in a class, she found that Σ x= 824 and that the standard deviation of x was 6.5​
i) Calculate Σ (x-50) and Σ (x-50)²​
ii) One person did the test earlier and her mark was 72. Calculate her new mean and standard deviation of the marks of all 17 people. ​
​
​
Thanks in advance Ali Railey​
Click to expand...

s1.jpg
 
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