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Statistcs 2: Jan09 Q3?

I am unsure how to do the second half of the question.

(The previous question has A=0.3)
"Each of cloth is inspected and those which contain too many flaws are classified as 'seconds' and sold at a lower price. The probability of a roll being classified as 'seconds' is 0.08"

1) Find the probability that, when 20 rolls are inspected, 2 or fewer will be classified as 'seconds'
2) Ten rolls of cloth of which 3 are 'seconds', are left in a store room. Six are selected at random. Find the probability that none of the six rolls selected is a 'second'.

OK I tried to do this but couldn't get the correct A value.
I did 0.3x20= 6 but with 6 I couldn't get n=20 value so it has confused me.

Can someone show me how each question is done step by step?
Reply 1
Avatar for Zacken
Zacken
22
Original post by KingAuthor

Can someone show me how each question is done step by step?


I'm not sure what your working out is suggesting, but you need to use the binomial distribution. Does that help?
(edited 8 years ago)
Reply 2
Avatar for KingAuthor
KingAuthor
OP
12
Original post by Zacken
I'm not sure what your working out is suggesting, but you need to use the binomial distribution. Does that help?


We haven't done binominal distribution, that's in S1. We've done S3 and S2 so far.


OH WAIT THAT REMINDS ME HAHAH
She told us to not do this question hahaha
omg
thank you ignore this post
Reply 3
Avatar for Zacken
Zacken
22
Original post by KingAuthor
We haven't done binominal distribution, that's in S1. We've done S3 and S2 so far.


OH WAIT THAT REMINDS ME HAHAH
She told us to not do this question hahaha
omg
thank you ignore this post


No problemo! :-)

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