2. [-/12 Points] DETAILS SCALCET8 2. 1.001.MI. A tank holds 1000 gallons of water, which drains from the bottom of the tank in half an hour. The values in the table show the volume V of water remaining in the tank (in gallons) after t minutes. t (min) 10 20 25 30 V (gal) 697 430 260 104 26 O (a) If P is the point (15, 260) on the graph of V, find the slopes of the secant lines PQ when Q is the point on the graph with the following values. (Round your answers to one decimal place.) O slope (5, 697) (10, 430) (20, 104) (25 , 26 ) (30, 0) (b) Estimate the slope of the tangent line at P by averaging the slopes of two adjacent secant lines. (Round your answer to one decimal place.) Submit