Statıstıcs I Deneme Sınavı Sorusu #835346
Consider the probability density function f(x)=0.025, for 20 ? x ? 60 and find the standard deviation of this function?
|
101/3 |
|
12.5 |
|
15 |
|
151/2 |
|
20 / 31/2 |
Yanıt Açıklaması:
m = E(X) = Int(-sonsuz , sonsuz)(....) = Int(20, 60)(x * f(x) dx) = Int(20, 60)(x * 0.025 * dx) = girdi(20, 60)((1/2) * x2 * 0.025) = (1/2) * 0.025 * (3600 - 400) = 0.25 * 160 = 40 ; V(X) = E(X - m)2 = Int(-sonsuz , sonsuz)(....) = Int(20, 60)((x - m)2 * f(x) dx) = Int(20, 60)((x - 40)2 * 0.025 * dx) = girdi(20, 60)((1/3) * (x - 40)3 * 0.025) = (1/3) * 0.025 * (8000 - (-8000)) = (1/3) * 0.25 * 1600 = 400/3 ; sd = (400/3)1/2 = 20 / 31/2 ; . pg. 184. Correct answer is E.
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