Answer: The price of the apartment.
Step-by-step explanation:
We know that for a given apartment, the number of bedrooms, bathrooms, and floor determines the price.
Then we could define the variables:
x = number of bedrooms.
y = number of bathrooms
z = floor.
And define the price of the apartment as a function of these variables:
p(x, y, z) = price
Then the independent variables are x, y, and z.
And the dependent variable (this is, the variable that changes in response to the changes in the independent variables) will be the price of the apartment.