Exercise $3$:

$$The returns of four stocks, A$,$ B$,$ C$,$ and D over a period of six years have been as follows:

$\backslash$table$[[,1,2,3,4,5,6]]$

$\backslash$table$[[$A$,10\%,12\%,-8\%,15\%,-2\%,20\%$