Jean Gray's total earnings over the past week was $3,925
Since Jean earns 4% for the first $2,00 business she does, she earns a base commission of = $2,000*0.04 = $80
Now, we need to find how of additional sales did Jean do over and above the base of $2,000. This is calculated as follows:
Total Sales = 3,925
Base sales =2,000
Add-on sales = 3,925-2,000 = 1,925
For the $1,925 sales, Jeans earns 8% commission, her commission for this will be 1,925*0.08 = $154
So, the total commission = $80 + $154 = $234
Her commission for the week was $234