All of Kola Company's sales are credit sales shipped free on board $($FOB$)$ shipping point. Kola typically records sales transactions $($that is$,$ sales and cost of sales$)$ throughout the year on the billing date. The internal auditor gathered the following information and documented it in his workpapers.

$\backslash$table$[[$Invoice Number,Date Shipped,Date Billed$],[8351,\frac{12}{28}\frac{?}{2019},\frac{12}{29}\frac{?}{2019}$