Question 839452: only 1 in 5 American women believe that the heart disease is her greatest health threat.” Suppose that 50 women are selected randomly and asked whether or not they believed that the heart disease is her greatest health threat.
a. What’s the expected number of women that believe that the heart disease is their greatest health threat?
b. What’s the probability that exactly 10 women believe that the heart disease is their greatest health threat?
c. What’s the probability that at least one woman believes that the heart disease is her greatest health threat?
d. What’s the probability that 25 or more women believe that the heart disease is their greatest health threat?
e. Find the variance and standard deviation of this distribution
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! only 1 in 5 American women believe that the heart disease is her greatest health threat.” Suppose that 50 women are selected randomly and asked whether or not they believed that the heart disease is her greatest health threat.
a. What’s the expected number of women that believe that the heart disease is their greatest health threat?
Ans: (1/5)50 = 10
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b. What’s the probability that exactly 10 women believe that the heart disease is their greatest health threat?
Ans: P(x = 10) = 50C10(1/5)^10*(4/5)^40 = binompdf(50,1/5,10)) = 0.1398
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c. What’s the probability that at least one woman believes that the heart disease is her greatest health threat?
P(at least one) = 1 - p(none) = (4/5)^50 = 0.00001427...
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d. What’s the probability that 25 or more women believe that the heart disease is their greatest health threat?
P(25<= x <=50) = 1 - binomcdf(50,1/5,24) = 0.00000209..
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e. Find the variance and standard deviation of this distribution
s^2 = npq = 50*1/5*4/5 = 8
s = 2sqrt(2)
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Cheers,
Stan H.
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