Calculus
Calculus1
Calculus
Multivariable Calculus
Partial Derivatives
Differential Equations
Differential Equations
Statistics
Probability
Basic Probability
Mathematical Statistics
Expectation
Expectations can be defined in a couple of different ways. It is the weighted average that uses the probability of all possible outcomes. In the discrete case, we can use the summation for all discrete cases, and in the continuous case, it will be an integration from $-\infty, \infty$.
So $E[X]=\sum_{i=1}^{\infty} x_ip_i(x)$ where x is the distinct values, and p(x) is the probability of the distribution $X$ which we are taking the expectation for is x.
The continuous case is defined by $E[X]=\int_{-\infty}^{\infty}xf(x)$ where x is defined same as the continuous case and f(x) is defined as the probability density function for the variable $X$