Final answer:
Heidi made a commission of $21.30 last week by selling $710 worth of jewelry. The jewelry store's earnings from these sales were $688.70 after paying out her commission.
Step-by-step explanation:
To calculate Heidi's commission from her sales, you convert the percentage to a decimal and then multiply it by the amount of her sales. In this case, she earns a 3% commission, which when converted to decimal is 0.03. Multiply this by her total sales for the week:
$710 × 0.03 = $21.30
Heidi's commission for last week is therefore $21.30.
To calculate how much the jewelry store made from her sales, you subtract Heidi's commission from the total sales:
$710 - $21.30 = $688.70
The store's earnings from Heidi's sales amount to $688.70.