3.根據(jù)樣本數(shù)據(jù)計(jì)算得平均每戶(hù)存款
試以95.45%(t=2)的置信度估計(jì)該地區(qū)平均每戶(hù)存款的置信區(qū)間為(
)
a.[25.82萬(wàn)元,30.44萬(wàn)元]
b.[26.97萬(wàn)元,29.28萬(wàn)元]
c. [20.22萬(wàn)元,34.20萬(wàn)元]
d.[5.05萬(wàn)元,51.21萬(wàn)元]
答案:a
解析:將數(shù)據(jù)帶入公式得:28.13+2*(23.08/20)=30.44;28.13-2*(23.08/20)=25.82