Answer:
80.32%
Step-by-step explanation:
The proportion who approved of the mayor :
p = number who approved of the mayor / total respondents = 1640 / 2000 = 0.82
The confidence interval for proportion is given by :
p ± Zcritical * √p(1 - p) / n
Zcritical at 95% = 1.96 (Z standard table distribution)
0.82 ± 1.96 * √0.82(0.18) / 2000
0.82 ± 1.96 * 0.0085906
0.82 ± 0.0168377
(0.8032 ; 0.8368)
Lower boundary = 0.8032
