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Statistics S2 eDexcel

"Find the probability of throwing three sixes twice in five throws of six dice."

I have spent the best part of the last hour trying to figure this out... Anyone know what to do?

Thanks in advance.
Original post by Kuchkuchhotahai
"Find the probability of throwing three sixes twice in five throws of six dice."

I have spent the best part of the last hour trying to figure this out... Anyone know what to do?

Thanks in advance.


So in this situation, there are a fixed number of trials, 2 possible outcomes (six, or not a six), and the probability of rolling a six is 1/6. You should recognise this as a certain type of distribution, linked with probability

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Original post by JoshBedford
So in this situation, there are a fixed number of trials, 2 possible outcomes (six, or not a six), and the probability of rolling a six is 1/6. You should recognise this as a certain type of distribution, linked with probability

Posted from TSR Mobile


I'm still SO lost, I use the following formula: nCr(P)^r(1-P)^n-r to work out my other answers... But I can't seem to figure it out for this question.

Is n=6 r=2? p=?

I'm so lost...
Reply 3
Original post by Kuchkuchhotahai
I'm still SO lost, I use the following formula: nCr(P)^r(1-P)^n-r to work out my other answers... But I can't seem to figure it out for this question.

Is n=6 r=2? p=?

I'm so lost...


If you write out the probability you're looking for beforehand, that should help you - eg. P(X > ..).
(edited 10 years ago)
Original post by vimto39
You shouldn't have to use the formula, answer is in table.


Lol
Reply 5
Original post by Kuchkuchhotahai
Lol


Just realised that's obviously not the case, sorry - only read the guys above and assumed it was a 50% probability haha.
I think the problem is worded very confusingly.
You are throwing six dice. You want exactly three of the six dice to land on a six. You are going to repeat this 5 times. What is the probability of this situation occurring twice?
Original post by vimto39
Just realised that's obviously not the case, sorry - only read the guys above and assumed it was a 50% probability haha.


Lol yeah I thought so..

Original post by JoshBedford
I think the problem is worded very confusingly.
You are throwing six dice. You want exactly three of the six dice to land on a six. You are going to repeat this 5 times. What is the probability of this situation occurring twice?


Okay..

So Let X be the probability of throwing three sixes..

P(X=2) X~Bin(6,P) ... Do I just find out P then?
Reply 9


Just in the process of doing the same for you! - Josh is bang on with method.


THANK YOU SO MUCH :biggrin:DD
I would never have thought of doing it like that!

Original post by vimto39
Just in the process of doing the same for you! - Josh is bang on with method.


Thanks for the help anyway, yeah Josh was spot on :biggrin:
Original post by Kuchkuchhotahai
THANK YOU SO MUCH :biggrin:DD
I would never have thought of doing it like that!



Thanks for the help anyway, yeah Josh was spot on :biggrin:

I actually really hate statistics haha
Original post by JoshBedford
I actually really hate statistics haha


Me too, I really should have done Mechanics or Decision Maths instead. I'm applying for an Econ/Maths degree so I had no choice :frown:

Which applied modules are you doing?
Original post by Kuchkuchhotahai
Me too, I really should have done Mechanics or Decision Maths instead. I'm applying for an Econ/Maths degree so I had no choice :frown:

Which applied modules are you doing?

My favorite is pure or mechanics, I did A level last year and did M1 and S1, doing M2 S2 and D1 this year. I hate D1 with a burning passion, so I'm self teaching M3 to make life a bit easier. It's basically the same as A2 physics, so it's relatively simple haha! I'll have to learn the classical mechanics anyway, so might as well do it now
Original post by JoshBedford
My favorite is pure or mechanics, I did A level last year and did M1 and S1, doing M2 S2 and D1 this year. I hate D1 with a burning passion, so I'm self teaching M3 to make life a bit easier. It's basically the same as A2 physics, so it's relatively simple haha! I'll have to learn the classical mechanics anyway, so might as well do it now


Haha I guess I could say the same, I did bits of Mechanics and found it much easier. However, there's no running from Statistics for me.. I have to do S2.

Oh really!? How would you go about comparing D1 with S2? Which of the two requires more effort and which seems harder to you?

What would you say is the hardest topic in S2? (Sorry to ask you all these questions, I'm currently doing a second run on my S2 book and want to be sure I know everything.)

:smile:
Original post by Kuchkuchhotahai
Haha I guess I could say the same, I did bits of Mechanics and found it much easier. However, there's no running from Statistics for me.. I have to do S2.

Oh really!? How would you go about comparing D1 with S2? Which of the two requires more effort and which seems harder to you?

What would you say is the hardest topic in S2? (Sorry to ask you all these questions, I'm currently doing a second run on my S2 book and want to be sure I know everything.)

:smile:

D1 is not 'maths', its about learning a process and repeating it in the exam. The actual algorithms and graph theory is very interesting and mathematical, but the way it's dumbed down for the module is insulting to the intricacies of it. I find D1 harder because I hate it and have no motivation to learn it.
The hardest topic in S2 is probably either hypothesis testing or just those definition questions.

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