If the student's fixed annual salary is $16,000 and her total earnings for the year are $47,000, then the amount she made from her commissions is $47,000 - $16,000 = $31,000.
This $31,000 is 3% of her total sales for the year, since her commission is 3%. To find out how much her total sales were, we can set up the equation:
3/100 * Total Sales = $31,000
Solving for Total Sales gives:
Total Sales = $31,000 / (3/100) = $1,033,333.33
So the student made about $1,033,333.33 in sales that year.