Answer:
Explanation
The confidence interval is defined by:
a. For a 90% confidence interval, z = 1.64. Then the confidence interval is: in my question z=1.64
b. For a 95% confidence interval, z = 1.96. The CI is: z=1.96
c. For a 99% confidence interval, z = 2.57. The CI is: z=2.57
I really don't know but i think this is it