5 Flashcards
Random variable?
A variable that assigns a numerical value to each outcome to a random experiment. As an example, the variable is like a function of the sample space.
In a random variable, the value you get at the end is or is not predictable and why?
It is not predictable because the outcome is not predicted.
Discrete random variable?
At the sample space, there are gaps between the possible values in that sample space.
Continuous random variables?
If you look at the sample space and notice no gaps.
If you take any two possibilities in a continuous random variable, could one of them NOT be possible?
No, they are all possible.
If you have a random variable, you should always ask yourself?
What is its probability distribution.
A probability distribution is?
A random variable X is a description that provides a method for computing the probability of ANY event contained in the sample space.
Cumulative probability distribution?
A random variable X is oven by the function F(x) = P(X <= x) for -oo < x < oo
If you have a discrete random variable and want to talk about the probability distribution function, you have to talk about?
The probability mass function.
Probability mass function (pmf)?
Gives a range of probabilities for discrete random variables
Probability density function (pdf)?
A random variable which it dos not gives out a probability.
Compliment rule of P(B^c)?
1 - P(B)
