Moment Generating Function 69Cbbb
1. The problem is to understand the moment generating function (MGF) and raw moments.
2. The moment generating function $M_X(t)$ of a random variable $X$ is defined as:
$$M_X(t) = E[e^{tX}]$$
where $E$ denotes the expected value.
3. The $n$th raw moment of $X$ is the expected value of $X^n$, denoted as:
$$\mu'_n = E[X^n]$$
4. The MGF can be used to find raw moments by differentiating it $n$ times with respect to $t$ and evaluating at $t=0$:
$$\mu'_n = M_X^{(n)}(0) = \left. \frac{d^n}{dt^n} M_X(t) \right|_{t=0}$$
5. This means the first raw moment (mean) is $\mu'_1 = M_X'(0)$, the second raw moment is $\mu'_2 = M_X''(0)$, and so on.
6. Important rules:
- The MGF uniquely determines the distribution if it exists in an open interval around zero.
- Raw moments provide information about the shape and spread of the distribution.
Final answer: The moment generating function $M_X(t) = E[e^{tX}]$ generates raw moments by differentiation: $\mu'_n = M_X^{(n)}(0)$.