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In a large population of high school students, 20% have experienced math anxiety. if you take a random sample of 10 students from this population, the probability that exactly two students have experienced math anxiety is ____.

Respuesta :

The probability is 0.302.

This is a binomial probability.  There are two outcomes; the probabilities are independent; and there is a fixed number of trials.  The probability is given by:

[tex]_nC_r(p)^r(1-p)^{n-r} \\ \\=_{10}C_2(0.2)^2(1-0.2)^{10-2}=_{10}C_2(0.2)^2(0.8)^8 \\ \\=45(0.2)^2(0.8)^8=0.30199\approx0.302[/tex]

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