statistics 2: post your doubts and solve mine! lol

[redapple20]

statistics experts plx line up here and save me from the "haunted examination hall"

 

[redapple20]

an unbiased dice is thrown once .mean 3.5 variance 35/12 . this dice is thrown 70 tyms
(a) find prob that mean score is less than 3.3

 

[redapple20]

water taken from a river contains on average 16 bacteria per ml .assumin poisson distrib find prob tat 5 ml of water contains
(a)65-85 bacteria inclusive
(b)exactly 80 bacteria

 

[OakMoon!]

an unbiased dice is thrown once .mean 3.5 variance 35/12 . this dice is thrown 70 tyms
(a) find prob that mean score is less than 3.3

mean for 70 times= 70*3.5. variance=70*35/12
Use SD and Mean to get probability from the normal distribution table.

 

[OakMoon!]

water taken from a river contains on average 16 bacteria per ml .assumin poisson distrib find prob tat 5 ml of water contains
(a)65-85 bacteria inclusive
(b)exactly 80 bacteria

Find mean of 5ml. 16*5=80
a) You need poission to normal approximation where the mean is 80 and variance is also equal to 80.
First do continuity correction:
P(65<=x<=85) is corrected to P(64.5<x<85.5) Now use the mean and variance to adjust these values and look up the normal distribution table.
b)Continuity correction of P(x=80) will be P(79.5<x<80.5). And then use normal distribution adjustment.

 

[redapple20]

Find mean of 5ml. 16*5=80
a) You need poission to normal approximation where the mean is 80 and variance is also equal to 80.
First do continuity correction:
P(65<=x<=85) is corrected to P(64.5<x<85.5) Now use the mean and variance to adjust these values and look up the normal distribution table.
b)Continuity correction of P(x=80) will be P(79.5<x<80.5). And then use normal distribution adjustment.

thantu but did u solve part b? The answer is not cumin

 

[redapple20]

mean for 70 times= 70*3.5. variance=70*35/12
Use SD and Mean to get probability from the normal distribution table.

Here I got da ans over nyt the n has to b divided frm the continuity correction and then the correct ans is cuming.

 

[redapple20]

The proportion of faulty cups made by factory machine is0.08. The cups are packed in 100s in boxes .4000required 4 a concert manager
orders 44 boxes. Find prob that these boxes will contain more than 4000 non faulty cups

 

[Zephyro]

The proportion of faulty cups made by factory machine is0.08. The cups are packed in 100s in boxes .4000required 4 a concert manager
orders 44 boxes. Find prob that these boxes will contain more than 4000 non faulty cups

1) p=0.92 n=44*100=4400
X~B(4400,0.92)
E(X)=np=4048 ; Var(X)=np(1-p)=323.84

Using Normal Approximation,
Y~N(4048,323.84)
P(X>4000) = P(X>4001)

Z= (4000.5-4048)/sqrt(323.84) sqrt of variance= standard deviation
Z=-2.64

I=0.9957(approx).

 

[redapple20]

Y wont we take >4000 y 4001?

 

[Zephyro]

Continuity Correction.

 

[redapple20]

Oh that's the same thing... acha plx tell me in da previous questions like watch above unbiased dice wala v did not take continuity o.5 but
v divided o.5 wid the value of n in thecase of that Q. 0.5/70 this was the new continuity correction y did v do IT? and wen do v use tat method
and wen do v simply take0.5??? Plz help... and thankooooooo!

 

[redapple20]

1) p=0.92 n=44*100=4400
X~B(4400,0.92)
E(X)=np=4048 ; Var(X)=np(1-p)=323.84

Using Normal Approximation,
Y~N(4048,323.84)
P(X>4000) = P(X>4001) and -2.64 on the table gives u 0.9959 not 0.9957

Z= (4000.5-4048)/sqrt(323.84) sqrt of variance= standard deviation
Z=-2.64

I=0.9957(approx).

 

[Zephyro]

Link me to the question paper please. Cant make out what your question is.

 

[redapple20]

C number 2 post here in stats post ur doubts

 

[Zephyro]

You divided because of Central Limit Theorm. There's no continuity correction in that question.

 

[redapple20]

You divided because of Central Limit Theorm. There's no continuity correction in that question.

Ok ye kub kub hota hai? This central limit theorum...

 

[Zephyro]

Ok ye kub kub hota hai? This central limit theorum...

Quite suprised you haven't learnt any of this in class.

 

[redapple20]

Lol course started march finished in April plx telll

 

[redapple20]

Helping or wat?