An article in Optical Engineering, "Operating curve extraction of a correlator's filter" (2004, Vol. 43, pp. 2775-2779) reported on use of an optical correlator to perform an experiment by varying brightness and contrast. The resulting modulation is characterized by the useful range of gray levels. The data are shown below: Brightness (%): 54 61 65 100 100 100 50 57 54 Contrast (%): 56 80 70 50 65 80 25 35 26 Useful range (ng): 96 50 50 112 96 80 155 144 255 (a) Test for significance of regression using a = 0.025. What is the P-value for this test? The regression model significant at a = 0.025. Choose the maximum possible lower estimate and the minimum possible upper estimate: