Answer:
Make a table with values of x and y using the equation y + 3 = -1/4(x - 3) :
x y
0 -2.25
3 -3
5 -3.5
-1 -2
-9 0
Now, graph these and draw a line through the points:
The answer for this equation is 540!
The IQR is the difference between Quartile 1 and Quartile 3
Q 1 = 17 and Q 3 = 30
Q3 - Q1 = 30 - 17 = 13