Mathematics: Post your doubts here!

[hassam]

well somebody tell wat trend CIE uses for class width....cos smtyms they are taking care of them.............smtym they r nt paying attention to them.....and how to give class boundaries given boundaries of the particular class.....m asking abt that 0.5 bit...........m hell cnfused in this topic

 

[redapple20]

Phle ans to btao? 120?

 

[mukki]

Please help!!!!!!!

1(i)
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s09_qp_6.pdf

225/900 is the probability that P(x>1002) hence standardize and solve

 

[Hehehaha]

225/900 is the probability that P(x>1002) hence standardize and solve

Still don't understand

 

[omar hazem]

itl be written in the qs that X follows a normal distribution or X-N
and i didnt get what u mean by p is not too far from 0.5...............Just check if np or nq >5

yeah i understand this, but i mean when we use the original value or the cc one ??

 

[mukki]

http://www.xtremepapers.com/community/threads/stats-how-to-solve-this-qs.16285/

plz any1 ans part 2 of this ques.

is it 2!*3p3?
*A*A*
* is the place where the ppl from area B will be placed and A is the place for the 2 guys from area A

 

[user]

Find the number of different ways in which the 9 letters of the word GREENGAGE can be
arranged if exactly two of the Gs are next to each other.
bt please...address my soln....dont post any other soln....i hv already done by an alternative way bt want to knw the problem with this method

aoa wr wb!
umm...i think when u keep 2 g's together....it'll include some combination where 3 of them are together, and we dont want that..

whats the alternative method u did...can u post?

 

[umarFM]

Please help!!!!!!!

1(i)
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s09_qp_6.pdf

Probability(Z>(1002-u)/8)=225/900
let (1002-u)/8) = a
1 - phi(a)=0.25
phi(a)=0.75
phi(a)=phi(0.674)
a=0.674
(1002-u)/8)=0.674
u=997

 

[mukki]

yeah i understand this, but i mean when we use the original value or the cc one ??

use the original value if its written in the qs that x follows a normal distribution if not then cc

 

[leosco1995]

well somebody tell wat trend CIE uses for class width....cos smtyms they are taking care of them.............smtym they r nt paying attention to them.....and how to give class boundaries given boundaries of the particular class.....m asking abt that 0.5 bit...........m hell cnfused in this topic

I am not sure, but I think you use boundaries (the 0.5 thing) when the data is discrete, i.e. when you can only have exact values (like in that question where there were 5000 students in a school)

 

[Hehehaha]

...am trying so hard now...
and this question
Q3 (ii) http://www.xtremepapers.com/papers/...S Level/Mathematics (9709)/9709_w09_qp_61.pdf

What is meant by least and greatest times? How to find?

 

[mukki]

...am trying so hard now...
and this question
Q3 (ii) http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_w09_qp_61.pdf

What is meant by least and greatest times? How to find?

here assume X1 as the least time for the journey and X2 has the greatest time for the journey. P(X1<x<X2)=.34
standardize to get P(-z1<Z<z2)=.34
then u get 2fi(z)-1=.34 solve and get fi inverse of the value. make the standardized equation and use the value that u have got once positive and once negative.

 

[Hehehaha]

Thank you so much guys...I seriously want to cry now

 

[umarFM]

yeah i understand this, but i mean when we use the original value or the cc one ??

original value value is used when the question is only of normal.... we use continuity correction when we convert from binomial to normal distribution....

 

[RGBM211]

1)Ten people travel in 2 cars,a saloon and a Mini.If the saloon has seats for 6 and the Mini has seats for 4,find the number of different ways in which the party can travel,assuming that the order of seating in each car does not matter and all the people can drive. Ans- 210
2)I have seven fruit bars to last the week. 2 are apricot, 3 are fig and 2 peach. I select one bar each day. In how many different orders can I eat the bars? Ans-210
If I select a fruit bar at random each day,what is the probability that I eat 2 apricot ones on consecutive days? Ans -2/7

Can someone try ...mmm not gtn the answer

 

[redapple20]

7!*6/3! or 8!/3! – 2 × 7!/3! = 5040 ways

 

[omar hazem]

original value value is used when the question is only of normal.... we use continuity correction when we convert from binomial to normal distribution....

yeah this is my point, when i know that i have to change from bionomial to normal??

 

[shan5674]

how many of youll think that youll are actually ready for stats tomorrow? coz some how i seem to be messing up in almost every single question i do and im not at all readyy...im freaking out like crazyyyyy i just wanted to know if im alone or if theres anyone who feels the same way :/ :'(

 

[redapple20]

Relax Ok! Sometimes its just tat we have not slept enough. And we cant do Qs. Sleep and try tomzz in da early morning

 

[mukki]

how many of youll think that youll are actually ready for stats tomorrow? coz some how i seem to be messing up in almost every single question i do and im not at all readyy...im freaking out like crazyyyyy i just wanted to know if im alone or if theres anyone who feels the same way :/ :'(

go to sleep dude wake up early in the morning and revise.. if u have stamina and if u wont get tired then wake up the whole time otherwise sleep. i recommend you to wake up at 6 study till 9 and then sleep till 12. wakeup but dont do anything then just go straight for ur paper