Nancy and Frank Products Ltd is trying to forecast Accounts Receivable. On Jan 1, 2020 it has $800 in Accounts Receivable. On average, 20% of sales are collected at the time of sale and 80% are collected the following month. Determine the month ending balance for Accounts Receivable for Jan, Feb and Mar if payments received in December are $1500. Sales for Dec, Jan, Feb and Mar are $2800, $2800, $2000 and $3800 respectively. You must show all your work and provide appropriate explanations for your calculations.