Age distribution in a city; votes for candidate hughes
7.31 Suppose the age distribution in a city is as follows:
Under 18 (22%) 18-25 (18%) 26-50 (36%) 51-65 (10%) over 65 (14%)
A researcher is conducting proportionate stratified random sampling with a sample size of 250. Approximately how many people should be sampled from each stratum? Do I use the z formula for sample proportions for n*p>5?
7.32 Candidate Hughes believes she will receive 55% of the total votes cast in her county. However, in an attempt to validate this figure, her pollster contacts a random sample of 600 registered voters in the county. The poll results show that 298 of the voters say they are committed to voting for her. If she actually has 55% of the total vote, what is the probability of getting a sample proportion this small or smaller? Do you think she actually has 55% of the vote? Why or why not?