Political scientists want to determine the probability of exactly 3 out of the next 5 voters they meet approving a proposal.

If the sample probability of the voters approving the proposal is 50%, the number of trials is and the number of successful trials is .

The probability that 3 out of the next 5 voters approving the proposal is

Respuesta :

Answer:

Probability that 3 out of the next 5 voters approving the proposal is 0.3125.

Step-by-step explanation:

We are given that the sample probability of the voters approving the proposal is 50% and Political scientists want to determine the probability of exactly 3 out of the next 5 voters they meet approving a proposal.

The above situation can be represented through binomial distribution;

[tex]P(X=r) = \binom{n}{r} \times p^{r} \times (1-p)^{n-r} ; x = 0,1,2,3,.....[/tex]

where, n = number of trials (samples) taken = 5

            r = number of success = exactly 3

            p = probability of success which in our question is probability of

                  the voters approving the proposal, i.e; p = 50%

Let X = Number of voters approving the proposal

So, X ~ Binom(n = 5 , p = 0.50)

Now, Probability that 3 out of the next 5 voters approving the proposal is given by = P(X = 3)

               P(X = 3)  =  [tex]\binom{5}{3} \times 0.50^{3} \times (1-0.50)^{5-3}[/tex]

                              =  [tex]10 \times 0.50^{3} \times 0.50^{2}[/tex]

                              =  0.3125