A research firm has determined that 80% of telephone
respondents will agree to answer an opinion poll. If 20
people are contacted, what is the probability that exactly 14
people agree to be polled?

Respuesta :

The probability that out of 20, 14 agree to answer is:

P(14) = 0.109

How to find the probability?

We know that the 80% of the respondents will agree to answer the opinion poll (and 20% don't).

Then the probability that a random respondent agrees to answer the poll is 0.8

Now, the probability that out of 20, 14 agree to answer, is:

[tex]P(14) = C(20, 14)*(0.8)^{14}*(0.2)^6[/tex]

Where C(20, 14) is the number of different combinations of 14 elements that we can make out of the 20 elements (the number of permutations).

[tex]C(20, 14) = \frac{20!}{(20 - 14)!*14!} = \frac{20*19*18*17*16*15}{6*5*4*3*2} = 38,760[/tex]

Replacing that in the probability, we get:

[tex]P(14) = 38,760*(0.8)^{14}*(0.2)^6 = 0.109[/tex]

If you want to learn more about probability, you can read:

https://brainly.com/question/251701