Consider a spreadsheet simulation model for a system in which the lead time for an order is distributed as follows:

Lead time

Probability

$1$ day

$\mathrm{.}2$

$2$ days

$\mathrm{.}3$

$3$ days

$\mathrm{.}4$

$4$ days

$\mathrm{.}1$

Suppose an Excel spreadsheet model has been partially created as shown below. what formula should be used to generate a lead time $($in days$)$ from this distribution?