To calculate her gross pay, we need to take into consideration, her total pay for the 4 days and her commission based on the total amount of goods she sold.
Firstly, her daily base salary is $85, since she worked for 4 days, her total salary for the four days will be $85 * 4 = $340.
Now, she is to earn 7.2% of $8,320 as commission. The amount of her commission is thus 7.2/100 * 8,320 = 599.04
