→ csro7788:展開P(|X-mu|<6simga) 括號裡面的就是35/36水準的I.C 01/30 19:10
→ yhliu:σ=√(400*1/2*1/2) = 10, 01/30 20:57
→ yhliu:P[200-6*10≦X≦200+6*10] = P[140≦X≦260] ≧ 35/36. 01/30 20:58
題目為
What does Chebyshev's theorem k=6(six standard deviation), for instance,
tell us about the number of heads we may get in 400 flips of a balanced coin?
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我的解法
P(|x-u|≦6σ)≧35/36
Heads of mean: 400 x 1/2 = 200
Number of heads: [200-200 x 35/36, 200+200 x 35/36] = [5.55, 394.5]
找不到信賴區間套用
不知這樣對不對
感謝
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