Final answer:
Rachel will earn an additional $250 this year due to the increase in commission rate from 4% to 4.5% on her $50,000 sales, resulting in a commission of $2,250 this year compared to $2,000 last year.
Step-by-step explanation:
To calculate how much more money Rachel will make this year with the increased commission rate, we need to compare the commissions from both years based on the same sales amount, which is $50,000. Last year, she earned a 4% commission, which can be calculated as follows:
$50,000 x 0.04 = $2,000.
This year, she earns a 4.5% commission, calculated as:
$50,000 x 0.045 = $2,250.
Subtracting last year's earnings from this year's:
$2,250 - $2,000 = $250.
Therefore, Rachel will make an additional $250 this year compared to last year.