Question #1 (10 points): A research group conducted a study on factors influencing 5-year
survival in breast cancer patients. They were particularly interested in patient's age and the
number of positive lymph nodes removed during surgery. The following figure shows the data
from 8 patients who survived after 5 years (the survivor group, green dots) and data from 9
patients who died within 5 years (the deceased group, red blocks). Please draw the decision
boundary using the nearest neighbor method (k-1) based on Euclidean distance.
Instructions: Identify pairs of closest data points from the survivor group and the deceased
group. Draw a perpendicular bisector for each pair. Connect these bisectors into a continuous
decision boundary.
No of Positive Lymph Nodes
42 10
14
12
8
O
+
2
IN
0
35 40 45 50 55 60 65 70
Age
Fig: 1