Answer:
p(x >788) = 0.0351
voted voters may be less than 788
Step-by-step explanation:
given data:
n =1072
p = 0.71
[tex]\mu =n*p = 1072*0.71 = 761.12[/tex]
nq = 1072*0.29 = 310.88
using below relation
[tex]\sigma = \sqrt{n*p*(1-p)} = 14.85[/tex]
as np and nq > 5, thus we can use normal approximation to binomial distribution i.e.
p(x >788) = 1 - p(x <788)
[tex]= 1 - p( \frac{x -\mu}{\sigma}) < (\frac{788 - 761.12}{14.85})[/tex]
= 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
