In a survey of 1072 people, 788 people said they voted in a recent presidential election. voting records show that 71% of eligible voters actually did vote. given that 71% of eligible voters actually did vote, (a) find the probability that among 1072 randomly selected voters, at least 788 actually did vote. (b) what do the results from part (a) suggest?

    p(x >788) = 0.0351

    voted voters may be less than 788

Step-by-step explanation:

given data:

n =1072

p = 0.71

nq = 1072*0.29 = 310.88

using below relation

as np and nq > 5, thus we can use normal approximation to binomial distribution i.e.

p(x >788) = 1 - p(x <788)

        = 1 - p (z <1.81)

         = 1 - 0.9649                              { from z tables}

    p(x >788) = 0.0351

b)This suggest that there is very less chance that among 1072 randomly selected voters, at least 788 actually did vote. Actually voted voters may be less than 788