求高人教 Statistics (Confidence Interval + Proportion) 感激~?

1.
Ans:
(1) 樣本數 < 30 , 故採用 t 分配
(2) 須有 breaking tension 之抽樣分配為常態分配之假設

2.
X/n = p-hat
E(X/n) = E(p-hat) = p
σ(X/n) = σ(p-hat) = √ [ p(1-p)/n ]
Ans:
mean = p
standard deviation = √ [ p(1-p)/n ]