Chapter 15 Flashcards
1
Q
What does FX(x) mean?
A
Cumulative distribution function
2
Q
Mean / E(x) formula
A
Sum X x px
Note May need to minus of previous probability if given cumulative in question
3
Q
Median
A
Probability 0.5 through the cumulative distribution
4
Q
E(ax +b) = …
A
aE(x) + b
5
Q
Variance formula
A
Var (x) = sum (x-mean)^2 x probability
6
Q
Skewness formula
A
Sum (x - mean) ^3
7
Q
Third central movement
A
1/n sum (x-mean)^3
8
Q
Skew x alternative
A
E(x) ^3 - 3 mean x E(x^2) + 2mean^3
9
Q
Coefficient of skewness
A
Skew(x) / Var(x)^3/2
10
Q
Non central moments
A
E(X^k)
11
Q
Central moments
A
SumE(X-mean)^k
12
Q
Moments about C
A
E(x-c)^k
