Answer:
Part A) see the explanation
Part B) see the explanation
Part C) see the explanation
Step-by-step explanation:
The complete question in the attached figure
Part A) Find and compare the slopes
we have
Function 1

This is a linear equation in slope intercept form

where
y is the price of the building in thousands
x is the floor area in square foot
m is the slope
b is the y-intercept
we have

Function 2
we know that
The formula to calculate the slope between two points is equal to

take two points from the data in the table
(400,32,000) and (700,56,000)
<u><em>Remember that the price in the table is in thousands</em></u>
substitute


The slope of the Function 2 is greater than the slope of the Function 1
The slope of the Function 2 is two times the slope of the Function 1
Part B) Find and compare the y-intercept
we know that
The y-intercept is the value of y when the value of x is equal to zero
Function 1

For x=0

Function 2
Find the equation in point slope form

we have

substitute

Convert to slope intercept form
isolate the variable y

For x=0

The y-intercept of the function 1 is $15,000 and the y-intercept of the function 2 is zero (the line passes through the origin)
Part C) Describe each function as proportional or non proportion
we know that
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form
or
In a proportional relationship the constant of proportionality k is equal to the slope m of the line and the line passes through the origin
so
Function 1
-----> is a non proportional linear function (because the line has a y-intercept)
Function 2
----> is a proportional linear equation (the line passes through the origin)