16,15,13,12,17,14,11,9,11,9,10,9 find the median, first quartile (Q1), and third quartile (Q3)

median = 11.5 . first quartile = 9.5 , third quartile = 14.5

Step-by-step explanation:

9,9,9,10,11,11,12,13,14,15,16,17

since there is an even number (12)

we can divide by 2

12 /2

= 6th position and 7th position

= 11 + 12

= 23 / 2 = 11.5

is also known as the lower quartile is half of the median position

6/2 = 3rd position and 7/2 = 3.5th position  

9 + 10 = 19

19 / 2 = 9.5

also known as upper quartile

is the position of median + position of lower quartile

= 6 +3 = 9th position and 7 +3 = 10th position

= 14 + 15 = 29

29/2 = 14.5

check above link.

graphically?   well, you graph them both, the solutions is where they both intersect each other, since there are two solutions, meaning they will meet twice, or namely the linear will run into the quadratic curve twice, and where they meet, those x,y coordinates are the solutions to the system.