9.44 Did you vote? A sample survey contacted an SRS of 663 registered voters in Oregon shortly after an election and asked respondents whether they had voted. Voter records show that 56% of registered voters had actually voted. We will see later that in this situation the proportion ot the sample who voted (call this proportion V) has approximately the Nor mal distribution with mean jj. = 0.56 and standard deviation CT =0.019.

(a) If the respondents answer truthfully, what is P(0.52 <
V < 0.60)? This is the probability that the sample proportion V estimates the population proportion 0.56 within plus or mi nus 0.04.
(h) In fact, 72% of the respondents said they had voted (V = 0.72). If respondents answer truthfully, what is P(V > 0.72)?
This probability is so small that it is good evidence that some people who did nor vote claimed that they did vote.