while finding variance

var(x)=E[X^2]-E^2

How to find this term : E[X^2]

while finding variance

var(x)=E[X^2]-E^2

How to find this term : E[X^2]

Hi @harshit8

You need to calculate the expected value of the squared random variable X .

For a discrete random variable X:

E[X^2] = \sum (x_i^2 \cdot p_i)

For a continuous random variable X (f(x) is density function):

E[X^2] = \int_{-\infty}^{\infty} x^2 f(x) \, dx

Hope this helps, feel free to ask if you need further help!

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