ISE261 Equations:
Binomial Distribution: b(x,n,p) = Cx,n px (1-p)n-x For 0,1,2,...,n E(X) = np
V(X) = np(1-p)
Negative Binomial: nb(x,r,p) = Cr-1,x+r-1 pr (1-p)x For 0,1,2,.. E(X) = r(1-p)/p
V(X) = r(1-p)/p2
Hypergeometric: h(x, n, M, N) = Cx,M * Cn-x,N-M / Cn,N E(X) = nM/N
V(X) = nM(N-M)(N-n)/N2(N-1)
Poisson: po(x, λ) = e–λ(λ)x/x!E(X) = λ
V(X) = λ+
Expected Value Discrete RV: E(X) = ∑ xi*p(xi) Continuous: E(X)= x f(x)dx
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Bayes' Theorem: P(Aj | B) = P(B|Aj)P(Aj) / ∑ P(B|Aj)P(Aj) For j = 1,...,k
Conditional Probability: P(A∩B) = P(A|B)*P(B)
Combination: Ck,n = n! / k!(n-k)! Permutation: Pk,n = n! / (n-k)!
Independence: P(A∩B) = P(A) * P(B)
Probability Property: P(A) = N(A) / N(T)
Addition Rule: P(A U B) = P(A) + P(B) - P(A∩B)
Complement: P(A) = 1 - P(A')
Uniform: f(x) = 1/ (b-a)for a ≤ x ≤ b
Z-transform: Z = (x - µ) / σ
Exponential CDF: F(x) = 1 – e–λt for t ≥ 0E(X) = 1/λ
V(X) = 1/λ2
Weibul CDF: F(x) = 1 – e–(x/) power α for x ≥ 0E(X) = β(1+1/α)
V(X)= 2{(1+2/)–[(1+1/)]2}
Gamma Function: (n) = (n-1)!( positive integer n); () = (-1) (-1); (1/2) =
Lognormal CDF: F(x) = [(ln(x) - ln) / ln] where { is the CDF of Z} E(x)= e µ+(σσ)/2
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Beta:f(x) = 1 (+) x-A B-xfor A x B
B-A ()() B-A B-A
E(X) = A + (B - A)( /( + ))
Gamma transform: F(x/, ) for x ≥ 0 E(x) = V(x) = 2
ISE 261 Equations Continued:
Two sided-CI for Mean (known σ): (L,U) = x_bar +/- (z/2 σ/ √(n))
Two sided-CI for Mean (small n ≤ 40): (L,U) = x_bar +/- (t/2,v s / √(n))
Two sided-CI for Mean (large n; > 40): (L,U)= x_bar +/- (z/2 s / √(n))
Two sided-CI for Variance: (L) = (n-1)s2/ χ2/2, n-1 (U) = (n-1)s2/ χ21-/2, n-1
Sample Size for Full Bound W: n = (2 z/2 / W)2
Sample Size for Half Bound B: n = ( z/2 / B)2
Z-transform: Z = (x - µ) / σ
+ +
E[h(X,Y)]=h(x,y)f(x,y)dxdyFor Discrete X&Y: E[h(X,Y)]=h(x,y)p(x,y)
- - x y
Cov(X,Y) = E(XY) - uxuy
Corr(X,Y) = Cov(X,Y)For Sampling Distributions:
x y (X_bar) = V(X_bar) = 2 / n
V(X) = E(X2) – E(X)2 E(T) = n V(T) = n2
HT for Mean (known σ)> Ζ =(x_bar - µ0) / (( / √(n))
HT for Mean (small n ≤ 40)> t = (x_bar - µ0) / ((s / √(n))
HT for Mean (large n; > 40)> Z = (x_bar - µ0) / ((s / √(n))
HT for Variance> χ2 = ((n-1) s2)/ 02
Beta Error for HT: a0 (Upper-Tail): β(u’) = [z+ ((u0 –u’)/ (/√(n))]
Beta Error for HT: a0 (Lower-Tail): β(u’) = 1 -[-z+ ((u0 –u’)/ (/√(n))]
Beta Error for HT: a≠0
β(u’) =[z/2+ ((u0 –u’)/ (/√(n))] - [-z/2+ ((u0 –u’)/ (/√(n))]
P_value for One Sided Tests: Upper tailed: P = 1 – Φ(z); Lower:P = Φ(z)
Two Sided Test: P_value = 2[1– Φ(|z|)]
Determining n ( known):
One-Sided HT for a given β(u’): n = (z+ z)2
u0 - u
Two-Sided HT for a given β(u’): n = (z/2+ z)2
u0 - u
Marginal pdf: +
fx(x) = f(x,y)dy for -x +
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