Answer:
a) 96% CI:
b) If we estimate that the fraction of voters is 0.57, we can claim with 96% confidence that the error is equal or less than 0.06 from the estimated proportion.
Step-by-step explanation:
The proportion of the sample is
The standard deviation of the sample proportion is
For a 96% CI, the z-value is z=1.751.
Then, the 96% CI can be written as:
b) If we estimate that the fraction of voters is 0.57, we can claim with 96% confidence that the error is equal or less than 0.06 from the estimated proportion.