Use the Pythagorean theorem.
If x is a hypotenuse, then we have:

If x is a leg, then we have:

Answer: 
Slopt in form ax+by=c is -a/b
-3/3=-1
slope is -1
intercept in form ax+by=c is c/b
63/3=9
slope is -1
intercept is at y=9
Quartile 3 is 130. Seventy-five percent of the data lies below Q3.
.75* 360= 270
270 is the answer