In a survey of 1126

Question

In a survey of

1126

​people,

750

people said they voted in a recent presidential election. Voting records show that

64​%

of eligible voters actually did vote. Given that

64​%

of eligible voters actually did​ vote, (a) find the probability that among

1126

randomly selected​ voters, at least

750

actually did vote.​ (b) What do the results from part​ (a) suggest?

Answer 1

phat = 750/1126 = 0.67

z = (0.67 - 0.64)/(sqrt(0.64*0.36//1126) = 2.1

P( p > 0..67) = P(z > 2.1) = 1 - P(z < 2.1) = 1 - 0.9821 = 0.0179

significantly more people who were eligible to vote in the presidential election voted