The (small) challenge here is to determine what the LCD is. Since 11, 17 and 3 are all prime, we find the LCD by multiplying them together: 561.
Then 9/11= 459/561; 15/17 = 495/561; and 2/3 = 375/561.
No. Quincy should have used the trend line to find the corresponding x value when y=80.
