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Reply 60
Hi guys
Is anyone else really confused with these definitions. I've been going through s2 past papers mark schemes up until 2002 to try and find a consistant difinition of what the exam board likes of those terms and they seem to vary a lot. there isn't a consistant response that they like to have. so i'mt not sure which response i'll give in 2morros exam for each term.
cheers
rajiv17
right, but can i find it throught the binomial method?


Yes you can but that will be an extremely long a tedious task. Looking at how much time you have in the exam and how many marks these type of questions are for, it's not really worth it. Most of the time, they will tell you when to use an approximation.
Reply 62
hartej91
Hi guys
Is anyone else really confused with these definitions. I've been going through s2 past papers mark schemes up until 2002 to try and find a consistant difinition of what the exam board likes of those terms and they seem to vary a lot. there isn't a consistant response that they like to have. so i'mt not sure which response i'll give in 2morros exam for each term.
cheers


Just quote word for word from the textbook, that's what we do in Physics.
For the two tailed hypothesis tests...
Can one of the probabilities be nowhere near the critical region and one be in it? Because I've done a question where the probably of getting less than or equal to the test statistic is like, 0.9983 and getting more than it is like 0.0137 and I don't really understand!
Do we need to know any proofs?

(I was thinking the Var(X) formula from the PDF of the Cumulative Uniform Distribution)
Reply 65
Liverpool F.C.™
Yes you can but that will be an extremely long a tedious task. Looking at how much time you have in the exam and how many marks these type of questions are for, it's not really worth it. Most of the time, they will tell you when to use an approximation.


i see...cheers mate :smile:
Reply 66
Does anyone have a guide or something to solving hypothesis questions? I know everything except how to do the hypothesis questions
Reply 67
sof geo
Does anyone have a guide or something to solving hypothesis questions? I know everything except how to do the hypothesis questions

Go here
Reply 68
Is everyone ready for tomorrow?
reem02
Is everyone ready for tomorrow?


No :emo:
I need some clarifcation/help on a s2 question.

Method 1 H(0) p=0.5, H(1) p not= 0.5
n=20 x=7, test at 10% significance

So I thought:
X~B(20,0.5) under Ho
Ho: p = 0.5
H1: p doesn't = 0.5... See more
Test x=7
Reject Ho if P(x=<7)<0.05

Use tables to find out P(x<=7)=0.1316.
0.1316>0.05
therefore not significant, do not reject ho.



Method 2 But the book says this is not right, and my teacher says:
H0 : p=0.5
h1: p not= 0.5
x=7, 10% sig
X - B(20, 0.5)... See more
P(X<=7)+P(X>=13)=2P(X<=7) = 2x0.1316 = 0.2632

0.2632 > 10% so not significant

Which is right, I don't understand why the first method is wrong- why do you need to consider P(x>=13) even if it is a two tailed test?

Thank you.
Does anyone know which past papers have particularly hard questions?
Reply 72
General Question.....when your dealing with critical regions ive always looked for the ones that are closest to the % significance they hav stated and jus wrote those as the C.R then the question would give like a number time sumthing happens for example...."sam flips coin 10 times n it lands on heads 7 times"
i would see if 7 is in my critical region and then come to my conclusions from there
Now this is the process ive been taught for doin hypothesis testing questions

In the mark schemes of papers im continually coming across a different method which i dont quite undastand would some1 pls clarify with me?
thnx
reem02
Is everyone ready for tomorrow?


Not even nearly!

I swear every time I do a question the method changes.
Reply 74
Can anyone help me with this question?

I can't work out part c, it's frustrating me! :frown:
18.5 HOURS LEFT :eek3:

F(m)=L
Jinxxeh
Can anyone help me with this question?

I can't work out part c, it's frustrating me! :frown:
You add them up and divide by two ... :confused:
Reply 77
Jinxxeh
Can anyone help me with this question?

I can't work out part c, it's frustrating me! :frown:
X=It's the value of the coin
samples.... mean
(10,10) 10
(10,20)(20,10) 15
(20,20) 20
(20,50)(50,20) 35
(50,50) 50
(50,10)(10,50) 30

u must continue on by calculating the probability of getting each mean of these
Jinxxeh
Can anyone help me with this question?

I can't work out part c, it's frustrating me! :frown:


You've gotta work out all the possible values the mean could take (from all the samples you listed in the earlier part), then work out what the probability of that value occuring is.
Then you make a grid thingy and that's a sampling distribution.
Reply 79
Jinxxeh
Can anyone help me with this question?

I can't work out part c, it's frustrating me! :frown:


Sampling distribtion means finding the probability of obtaining each sample so you got find the probabilty of getting each different sample combination that you have in the previous part

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