Write a MATLAB program to evaluate the following mathematical expression. The equation should utilize variables for $x,,$ and $.$ For example, you might run the program with $x=1,=2,$ and $=3.$

$P=\frac{1}{\sqrt[\phantom{2}]{2}}{e}^{-\frac{(x-{)}^2}{2{}^2}}$

This program calculates a Gaussian normal distribution.

Note: In MATLAB Grader the variables $x,$ mu$,$ and sigma have already been defined for you. You should not create new $x,$ mu$,$ and sigma variables.