Expected Value - Section 6.1

Front

What is the standard deviation of a random variable?

Back

The standard deviation of a random variable is a measure of how much the values of the variable differ from the mean.

Front

What is the expected value of a random variable?

Back

The expected value is the average of all possible values of a random variable, weighted by their probabilities.

Front

How do you calculate the expected value from a probability distribution?

Back

Multiply each possible value by its probability and sum all the results.

Front

What is a discrete random variable?

Back

A discrete random variable is one that can take on a countable number of values.

Front

What is an example of a discrete random variable?

Back

The annual number of sweepstakes winners from New York City.

Front

What is the formula for expected value (E) in a probability distribution?

Back

E(X) = Σ [x * P(x)], where x is a value and P(x) is its probability.

Front

What does it mean if a random variable has a standard deviation of zero?

Back

It means that all values of the random variable are the same and there is no variability.

Front

What is the expected value of Eva's coin flip if she wins $4 for heads and loses $3 for tails?

Back

$0.50.

Front

What is the mean of a probability distribution?

Back

The mean is the same as the expected value and represents the average outcome.

Front

What is the probability of an event?

Back

The probability of an event is a measure of the likelihood that the event will occur, ranging from 0 to 1.