Let x be Gaussian with mean mu _(x) and variance sigma _(x)^(2), and let Y be Gaussian with mean mu _(Y) and variance
sigma _(Y)^(2). Show that if x,Y are assumed independent, then Z=x+Y is Gaussian with mean mu _(x)+mu _(Y)
and variance sigma _(x)^(2)+sigma _(Y)^(2).
Hint: Write x=ar{x} +mu _(x),Y()/(b)=ar (Y)+mu _(Y) and show, using the convolution identity, that the law of
/bar (Z)=ar{x} (+)/(b)ar (Y) is Gaussian with mean 0 and variance sigma _(x)^(2)+sigma _(Y)^(2).
2. Let X be Gaussian with mean x and variance ox, and let Y be Gaussian with mean y and variance y. Show that if X,Y are assumed independent, then Z = X + Y is Gaussian with mean x + Y and variance ox +oy.
Hint: Write X = X + x,Y = Y + y and show, using the convolution identity, that the law of Z = X + Y is Gaussian with mean 0 and variance ox + oy.