Answer: (31.75%, 36.25%)
Explanation:
Let p be the proportion of workers in this city who have full health insurance coverage.
As per given,
Sample size : n= 170
Number of workers who had full health insurance coverage.=578
i.e. sample proportion:

Also, z-score for 95% confidence level : 1.96
Formula to find the confidence interval for p :



Hence, a 95% confidence interval for the true percent of workers in this city who have full health insurance coverage= (31.75%, 36.25%)