Problem $3$a $(15$ points$)$:

$($a$)$ Develop a user defined function "MyVar" that calculates a variance by using the following equation: MyVar$=\frac{{\displaystyle \underset{i=1}{\overset{n}{}}}\sqrt[\phantom{2}]{(3x_i^2-\text{A}\text{v}\text{g})}}{2n-1}$ where Avg represents the average of variable $x_i.$ Use the values given on the sheet $"$P$3$a$"$ to test the function. Remember that this function must have three arguments $(x,$Avg, and $n$