Final answer:
Isabelle needs to save a minimum of $115.50 per month to cover her portion of the first year's tuition.
Step-by-step explanation:
To find the minimum monthly amount Isabelle needs to save, we first need to calculate her portion of the annual tuition. Since her parents will be paying 75% of the tuition, Isabelle will need to pay the remaining 25%. To find this amount, we can multiply the annual tuition by 25% (or 0.25). So, her portion of the tuition is $5,544 x 0.25 = $1,386.
Isabelle has one year to save this amount, so we can divide the total by 12 to find the minimum monthly amount she needs to save. $1,386 ÷ 12 = $115.50.
Therefore, Isabelle needs to save a minimum of $115.50 per month to cover her portion of the first year's tuition.