Light intensity is a measure of the strength produced by a light source. The table below compares the intensity of light measured from various distances away from the source. Distance 0.20 r (m) 0.30 0.40 0.50 0.60 0.70 0.80 1.00 1.20 1.40 Intensity. I (units) 32.50 14.44 8.13 5.20 3.61 2.65 2.03 1.3 0.9 0.66 Given that the intensity of light varies inversely with the square of the distance from the light, use any two co-ordinates to find the value of the constant of variation, k, correct to 2 significant figures.