Hi Guys

I am trying to find the expected value of Y given that Y>0 and Y ~ N(-3,16)

The answer I get is not reasonable so I am trying to work out where I went wrong.

I used integration using substitution, using z = (x+3)/4 and after splitting up the integral, arrived at an integral (between 3/4 and infinity) minus 2 * P(Z>3/4)

After working out the value for E(x) I get a negative number.

Any help would be appreciated,

Thanks,

Thomas