An Italian company is planning it's inventory levels determine the planned service level. Therefore, it needs to check probability of stock. The business guidelines promise a Service Level of $98\%.$ What amount of inventory should be used to match the guideline?

$\backslash$table$[[$Demand$,3,8,9,10,12,18,20],[$Probability$,0\mathrm{.}05,0\mathrm{.}1,0\mathrm{.}2,0\mathrm{.}4,0\mathrm{.}2,0\mathrm{.}03,0\mathrm{.}02]]$