maths_arghh234
Junior Member
- Joined
- Nov 8, 2009
- Messages
- 52
hi i'm stuck on distributions again !!.. i've got 3 qusetions all have parts a,b and c .. and i'm stuck on part c of all of them so this is the first question
4 it is claimed the 95% of the population in a certain village are right- handed. a random sample of 80 villages are tested to see if they are right-handed or left-handed . use a poisson approximation to estimate the probability that the number who are right handed is
X is the number of left handed people (that;s how i've worked out a and b) X-B(80,0.05)
X=P(4)
a) 80 b)79 c) at least 78 so with a. x=0 which is e-4 = 0.0183
b. 79 right- handed X=1 (e to the power of -4)(4 to the power of 1) /1!
c. is where i'm stuck i tried it but the answer was wrong (the answer are at the back of the question book) i think i'm getting the numbers wrong ..
. if the number of right- handed people are at least 78
then X< ar equall to 2 .. that's what i worked anyway .. :\
4 it is claimed the 95% of the population in a certain village are right- handed. a random sample of 80 villages are tested to see if they are right-handed or left-handed . use a poisson approximation to estimate the probability that the number who are right handed is
X is the number of left handed people (that;s how i've worked out a and b) X-B(80,0.05)
X=P(4)
a) 80 b)79 c) at least 78 so with a. x=0 which is e-4 = 0.0183
b. 79 right- handed X=1 (e to the power of -4)(4 to the power of 1) /1!
c. is where i'm stuck i tried it but the answer was wrong (the answer are at the back of the question book) i think i'm getting the numbers wrong ..
. if the number of right- handed people are at least 78
then X< ar equall to 2 .. that's what i worked anyway .. :\