Calculate E(x^2) Given I.I.D. N(0,1) Random Variables

  • Thread starter Thread starter James1990
  • Start date Start date
  • Tags Tags
    Expectation
AI Thread Summary
To calculate E(x^2) for i.i.d. random variables distributed as N(0,1), one can use the relationship between variance and moments. The variance of a standard normal distribution is 1, and the mean is 0. Applying the formula Var(X) = E[X^2] - {E[X]}^2, we find that E[X] = 0 simplifies the equation to E[X^2] = Var(X). Therefore, E(x^2) equals 1 for standard normal random variables. Understanding these properties is essential for accurate calculations.
James1990
Messages
2
Reaction score
0
How to calculate E(x^2) given that x are i.i.d random variables distributed as a standard normal i.e. N(0,1) ?
Thank you.
 
Physics news on Phys.org
James1990 said:
How to calculate E(x^2) given that x are i.i.d random variables distributed as a standard normal i.e. N(0,1) ?
Thank you.

Hey James1990 and welcome to the forums.

Do you know the relationship for Variance to second and first order moments?

[HINT: Var(X) = E[X^2] - {E[X]}^2].

What do you know about the mean and variance of your distribution?
 
I was reading a Bachelor thesis on Peano Arithmetic (PA). PA has the following axioms (not including the induction schema): $$\begin{align} & (A1) ~~~~ \forall x \neg (x + 1 = 0) \nonumber \\ & (A2) ~~~~ \forall xy (x + 1 =y + 1 \to x = y) \nonumber \\ & (A3) ~~~~ \forall x (x + 0 = x) \nonumber \\ & (A4) ~~~~ \forall xy (x + (y +1) = (x + y ) + 1) \nonumber \\ & (A5) ~~~~ \forall x (x \cdot 0 = 0) \nonumber \\ & (A6) ~~~~ \forall xy (x \cdot (y + 1) = (x \cdot y) + x) \nonumber...
I was reading documentation about the soundness and completeness of logic formal systems. Consider the following $$\vdash_S \phi$$ where ##S## is the proof-system making part the formal system and ##\phi## is a wff (well formed formula) of the formal language. Note the blank on left of the turnstile symbol ##\vdash_S##, as far as I can tell it actually represents the empty set. So what does it mean ? I guess it actually means ##\phi## is a theorem of the formal system, i.e. there is a...
Back
Top