Answer:
a.(0.17; 0.21)
Explanation:
The confidence interval is always centered at the mean of the sample you take. In this case, the average value of the sample is 38/200 = 0.19. The only interval of length 0.04 centered at 0.19 is (0.17; 0.21). Note that the intervals should have length 0.04 in order for the margin of error to be 0.02.