Under her cell phone plan, Micaela pays a flat cost of $47.50 per month and $4 per gigabyte, or part of a gigabyte. (For example, if she used 2.3 gigabytes, she would have to pay for 3 whole gigabytes.) She wants to keep her bill under $55 per month. What is the maximum whole number of gigabytes of data she can use while staying within her budget?
Let's assume Micaela uses x gigabytes of data.
The cost of the data usage is 4x dollars.
The total cost including the flat cost for the plan is 47.50 + 4x dollars.
According to the condition, this total cost should be less than $55.
So, we have the inequality:
47.50 + 4x < 55
Subtracting 47.50 from both sides, we get:
4x < 55 - 47.50
4x < 7.5
Dividing both sides by 4, we get:
x < 7.5/4
x < 1.875
Since Micaela needs to pay for whole gigabytes of data, the maximum whole number of gigabytes she can use while staying within her budget is $\boxed{1}$.
To find the maximum whole number of gigabytes of data Micaela can use while staying within her budget, we need to set up an inequality based on the information given.
Let's denote the number of gigabytes as "x."
According to the problem, Micaela pays $47.50 per month flat cost in addition to $4 per gigabyte. So the total cost is given by:
Total Cost = Flat Cost + Cost per Gigabyte * Number of Gigabytes
Total Cost = $47.50 + $4 * x
She wants to keep her bill under $55 per month, so we can set up the following inequality:
$47.50 + $4 * x ≤ $55
Now, let's solve the inequality:
$4 * x ≤ $55 - $47.50
$4 * x ≤ $7.50
Divide both sides by $4:
x ≤ $7.50 / $4
x ≤ 1.875
Since we are looking for the maximum whole number of gigabytes, we must consider the largest whole number less than or equal to 1.875, which is 1.
Therefore, Micaela can use a maximum of 1 whole gigabyte of data while staying within her budget.