1. "Test the residuals of two other points to determine how well the line of best fit models the data."

The main problem I'm having here is finding where to get my observed value and my predicted value.

This is my chart:
Arm Span (inches) Height (inches)
58 60
49 47
51 55
19 25
37 39
44 45
47 49
36 35
41 40
46 50
58 61