Jean's commission is 4% of all her sales, this means that if she sells a total of $100, her commission will be $4.
Given that her sales have a total worth of $4073 to determine how much she will earn in commission you have to calculate the 4% of $4073.
For this, you have to multiply 4073 by 4 and divide the result by 100
That week she'll earn a commission of $162.92