Probabilty Flashcards
1
Q
Types of random variable
A
Discrete random variable
Continuous random variable
2
Q
What is discrete random variable
A
This is one which takes on only whole numbers (integer numbers)
3
Q
What is continuous random variable
A
It takes on values within an interval
4
Q
Probability distribution of discrete random variable
A
Y p(y) n(y) y(p(y) y^2 y^2py
To get p
Ncn x ncn
N(y)=p
While multiplying y(p(y)), only multiply the numerator
Eg 2x18/84 = 36/84
5
Q
Expected value
A
Exp(x)
6
Q
Variance
A
E(x)^2 = Ex^2p(x)
7
Q
To find what’s in the squares on joint distribution
A
Eg 1 2 3 A b c 0 0 3 0 1 2
First square = 3c3= 1
0 0 3 0 1 2 0 2 1 0 3 0 1 0 2 1 1 1 1 2 0 1 3 0
8
Q
Second table in joint distribution
A
Py
Yp(y)
Y2p(y)
9
Q
Variance in joint distribution
A
Ex^2p(x) - Exp(x)
10
Q
Covariance
A
E(xy) - e(x). E(y)
