Focal length versus apparent magnification

Note that magnification as used in this document is not conformant to the optics definition

xy scatter graph background rectangle major grid lines axes x-axis and y-axis coordinate labels for the rectangles above (18.5,3.2) (20,2.8) (23,2.3) (34,1.3) linear regression line data points as circles text layers Focal length versus magnification Four different magnifying glasses Focal length (cm) Apparent magnification y-axis labels 1 1 2 2 2 2 2 3 3 3 3 x-axis labels 18.5 20 22 23 25 26 28 29 31 32 34

y =-0.11x + 5.08

Best fit relationship actually appears to be: f(x) = 75.85*(1/x)-0.96 r² = 1

Data table

Focal length (cm)Apparent magnification
18.53.20
202.80
232.30
341.30