Question

A random variable X takes values 1, 2, 3, 4 with
1/6, 1/3, 1/3,1/6
probabilities
respectively, then its
mean and variance are_______​

Answer 1

Answer:

A random variable is a variable taking on numerical values determined by the outcome of a random phenomenon.

The probability distribution of a random variable

x

tells us what the possible values of

x

are and what probabilities are assigned to those values.

A discrete random variable has a countable number of possible values.

The probability of each value of a discrete random variable is between 0 and 1, and the sum of all the probabilities is equal to 1.

A continuous random variable takes on all the values in some interval of numbers.

A density curve describes the probability distribution of a continuous random variable, and the probability of a range of events is found by taking the area under the curve.