expected value of a 1*4 matrix

how can i find expected value k=E{(z.^2)*transpose(z)}.

'z' is a 1*4 matrix.

is matlab command mean((z.^2)*transpose(z)) is equal to expected value E{...}??

thanks

Answer 1

[Matt J]

Yes. mean(x) averages over x.

[ali]

thank you Matt J

[Muhammad Yasir]

I have one confusion in this regard is that expected value is not always equal to the mean.

In a book on probability theory, I have found the following definition of expected value of a random variable :

where is the average value taken by a random varibale with probaility

[Matt J]

Yes, but the law of large numbers implies that the arithmetic mean, as given by mean(), will approximate the statistical expected value.

https://en.wikipedia.org/wiki/Law_of_large_numbers#Forms