It has been estimated that 7000 of the 15000 voting residents...?

K

Kelly B

New member
It has been estimated that 7000 of the 15000 voting residents in your community vote for Party A. If 10 eligible voters from the town are randomly chosen:

a.) Does this scenario represent a binomial or hypergeometric distribution?

b.) What is the probability that at least four residents will vote for Party A?

MY ANSWERS:

a.) This scenario is binominal.

b.) I need help starting this one ... after this point I'm having lots of trouble.

(p>4) = p(x=0)+p(x=1)+p(x=2)+p(x=3)
 
Let be X: number of voting residents in your community vote for Party A

p = 7000/15000 = 0.467
q = 0.533
n = 10

b)

P(X 4) = 1- P(X 3)

P(X 3) = P(X=0) + P(X=1) + P(X=2) + P(X=3)

Lokk for the tabe.
 
At least 4 means, p(x=4) + p(x=5) + p(x=6) + p(x=7) + p(x=8) + p(x=9) + p(x=10)

but it's easier to find the probability of 0,1,2,3 and find the difference

10C0 x (7000/15000)^0 x (8/15)^10
and so on
10C1 x (7/15)^1 x (8/15)^9
 
Let be X: number of voting residents in your community vote for Party A

p = 7000/15000 = 0.467
q = 0.533
n = 10

b)

P(X 4) = 1- P(X 3)

P(X 3) = P(X=0) + P(X=1) + P(X=2) + P(X=3)

Lokk for the tabe.
 
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