Hello, please answer and explain :

Figure 3 . Experimental setup for measuring focal lengthTable 3 - Object and image distances for the lens Object distance Image distance, p (cm) g (cm) + 0.1 cm + 0.1 cm 20.0 54.6 22.0 42.4 24.0 37.4 26.0 33.0 28.0 30.4 30.0 28.6 32.0 26.8 34.0 25.6 36.0 24.4 38.0 23.8 40.0 23.0Graph 2: the inverse of the image distance (1/q) vs to the inverse of the object distance (1/p) for the lens. Data Set 1/p 1/q (cm) (cm) 1 0.05 0.01831 0.045 0.02358 0. 0417 0. 02673 0. 038 0. 03034 0.036 0. 03285 0.033 0.0349 0. 03125 0.03731 0.04 - 8 0.02941 0. 039BE 9 0.02777 0. 04098 10 0. 02631 0. 84201 Linear Fit for: Data Set | L'inverse de la distance image 0.025 0. 84347 1/q = mx4b m (Slope): -1,003 +/- 0.01012 em/em b [Y-Intercept): 0.06856 +/- 0.0003613 em Correlation: -0.9895 RMSE: 0.0002593 cm L'inverse de la distance image (cm) 0.03 0.02 - 0.03 0.04 0.05 (4x:0.025000 Ay:0) Ll'inverse de la distance objet (em)