9. A poll of 2100 people showed that 53% of people will vote for Joshua for Mayor of Disneyland. The results are considered accurate to within 2.8%, 18 times out of 20. a. Determine the confidence level of this poll. (1 point) b. Determine the confidence interval of the poll. Write your answer in two different ways. (2 points) c. If a group of 3500 people was surveyed, calculate the range of people who would vote for Joshua. (1 point) d. Explain why the margin of error would decrease if the sample size of the poll increased. (1 point)