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12 terms

Ap Statistics formulas

Forumulas for stats
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Sample mean
x = ( Σ xi ) / n
Sample standard deviation
s = sqrt [ Σ ( xi - x )2 / ( n - 1 ) ]
Pooled sample standard error
s pooled = sqrt [ (n1 - 1) s12 + (n2 - 1) s22 ] / (n1 + n2 - 2) ]
Simple linear regression line
ŷ = b0 + b1x
Regression coefficient
b1 = Σ [ (xi - x) (yi - y) ] / Σ [ (xi - x)2]
Regression slope intercept
b0 = y - b1 * x
Sample correlation coefficient
r = [ 1 / (n - 1) ] Σ { [ (xi - x) / sx ] * [ (yi - y) / sy ] }
Standard error of regression slope
sb1 = sqrt [ Σ(yi - ŷi)2 / (n - 2) ] / sqrt [ Σ(xi - x)2 ]
Rule of addition
P(A ∪ B) = P(A) + P(B) - P(A ∩ B)
Rule of multiplication
P(A ∩ B) = P(A) P(B|A)
Expected value of X
E(X) = μx = Σ [ xi * P(xi) ]
Variance of X
σ2 = Σ [ xi - E(x) ]2 P(xi) = Σ [ xi - μx ]2 ]2 * P(xi)