It is the first time to ask question here. I have a question in my assignment cannot solve, plx help me to solve that question, plx, plx, i reli need the answer, otherwise, i will very sad ga
Let x~N(u, a^2). Find k such that P(u-ka < x < u+2ka) =0.8.
where the a is the sigma, i cannot type it in IE, so use a instead.
thx!!! ^^
Plx help me to solve the question of normal distrubution
2007-10-17 8:11 am
回答 (2)
2007-10-17 10:44 am
✔ 最佳答案
Let x~N(u, σ^2). Find k such that P(u- kσ < x < u+2kσ) =0.8.where the σ is the sigma
P(u- kσ < x < u+2kσ)
=P[(u- kσ-u)/σ <(x-u)/σ < (u+2kσ-u)/σ]
=P[- k < Z < 2k]
P(u- kσ < x < u+2kσ)=0.8
P(- k < Z < 2k)=0.8
Φ(2k)-Φ(-k)=0.8
Φ(2k)+Φ(k)-1=0.8
Φ(2k)+Φ(k)=1.8
k=0.95 (use trial and error)
2007-10-22 10:48 pm
你可以問老師ga
收錄日期: 2021-04-13 14:31:52
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20071017000051KK00065