Solution :
Given that,
Point estimate = sample proportion = = x / n = 23 / 43 = 0.535
1 - = 1 - 0.535 = 0.465
Z/2 = Z0.005 = 2.576
Margin of error = E = Z / 2 * (( * (1 - )) / n)
= 2.576 (((0.535 * 0.465) / 43)
= 0.196
A 99% confidence interval for population proportion p is ,
- E < p < + E
0.535 - 0.196 < p < 0.535 + 0.196
0.339 < p < 0.731
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