Respuesta :
Answer:
a) 2.3
b) 1.4
c) 1.2
d) On average, 2.3 out of 6 women would consider themselves baseball fans. The standard deviation is 1.2 women, so in most samples of 6 women, the number of women who consider themselves baseball fans would differ from the mean by no more than 1.2.
Step-by-step explanation:
For each woman, there are only two possible outcoes. Either they are a fan of professional baseball, or they are not. The prbability of a woman being a fan of professional baseball is independent of other woman. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
Probability of exactly x sucesses on n repeated trials, with p probability.
Can be approximated to a normal distribution, using the expected value and the standard deviation.
The expected value of the binomial distribution is:
[tex]E(X) = np[/tex]
The variance of the binomial distribution is:
[tex]V(X) = np(1-p)[/tex]
The standard deviation of the binomial distribution is:
[tex]\sqrt{V(X)} = \sqrt{np(1-p)}[/tex]
38% of women consider themselves fans of professional baseball.
This means that [tex]p = 0.38[/tex]
Six women are sampled:
This means that [tex]n = 6[/tex]
(a) Find the mean of the binomial distribution.
[tex]E(X) = np = 6*0.38 = 2.3[/tex]
(b) Find the variance of the binomial distribution
[tex]V(X) = np(1-p) = 6*0.38*0.62 = 1.4[/tex]
(c) Find the standard deviation of the binomial distribution.
[tex]\sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{6*0.38*0.62} = 1.2[/tex]
(d) Interpret the results in the context of theâ real-life situation.
On average, 2.3 out of 6 women would consider themselves baseball fans. The standard deviation is 1.2 women, so in most samples of 6 women, the number of women who consider themselves baseball fans would differ from the mean by no more than 1.2.