Statistics (S1)!

[aseelabdulghani]

Hello everyone, im attending for the statistics exam on november 5... if its possible i need some help with precious notes and anything that can help in my studying Thanks.

 

[Mikaila]

I need help in Normal Distribution!

 

[Bilegdemberel_rj]

I need help in Normal Distribution too. Less than 25, so I wrote P(25-miu /sigma) but it led to wrong answer. I should have written 24.5 WHY?

 

[panpan101]

For normal distribution, know how to:
write the distribution X~N(mean, variance)
using approximation to relate with Binomial Distribution where np=mean npq=variance
know how to read from Norm Dist Table
know how to interpret and use the normal graph (Bell shaped)
know how to express X into Z (standard normal)
use the formula X-(MEAN) / (STAN DEV)

For approximation if
P(X>0) = P(X>0.5)
P(X<0) = P(X<-0.5)
P(X>(or equal to) 0) = P(X>-0.5)
P(X<(or equal to) 0) = P(X<0.5)

Less than 25 probably means that P(X<24.5) after approximation

Sorry if this is too brief... but... i dont know any easier methods to explain through typing.

 

[Soubia Sabrin]

Are u all appearing on 5th?

 

[Rutzaba]

Are u all appearing on 5th?

wat subjects do u have doubt in?

 

[Soubia Sabrin]

wat subjects do u have doubt in?

Mostly Probability Distribution n Normal Distribution! Any special tips for those? :/

 

[Rutzaba]

Mostly Probability Distribution n Normal Distribution! Any special tips for those? :/

practice sweetheart... and is u dun get questions ask

 

[Soubia Sabrin]

practice sweetheart... and is u dun get questions ask

Thanks dear! ^_^ Did u appear for A level Maths?

 

[Rutzaba]

Thanks dear! ^_^ Did u appear for A level Maths?

yeah i did.

 

[mnotanerd]

1 It is known that, on average, 2 people in 5 in a certain country are overweight. A random sample of
400 people is chosen. Using a suitable approximation, find the probability that fewer than 165 people
in the sample are overweight.
A box contains 300 discs of different colours. There are 100 pink discs, 100 blue discs and 100 orange
discs. The discs of each colour are numbered from 0 to 99. Five discs are selected at random, one at
a time, with replacement. Find
(i) the probability that no orange discs are selected, [1]
(ii) the probability that exactly 2 discs with numbers ending in a 6 are selected, [3]
(iii) the probability that exactly 2 orange discs with numbers ending in a 6 are selected, [2]
(iv) the mean and variance of the number of pink discs selected.

please help me with these questions

 

[abdul arham]

overveit probablity=2/5
n=400
np=mean=160which is greater than 5
npq=varience=96 which is greater than 5
using suitable aproximation ven mean and varience greatwer than 5 we have
x=164.5 not 165(first learn approximation how much and ven it is used)
then use formula fi of(164.5-160)divided by underrot of 96 and find probablity in table

 

[Batguy]

i need table

 

[Rutzaba]

i need table

http://course.shufe.edu.cn/jpkc/jrjlx/ref/StaTable.pdf

 

[Igcse stuff]

I aslo need s1 notes