A keyboarder's speed over a 4-min interval is given by the following function, where W(t) . Ay + is the speed, in words per minute, at time t. W ( t) = - 3t + 6t+ 24 20- a) Find the speed at the beginning of the interval. b) Find the maximum speed and when it occurs. c) Find the average speed over the 4-min interval. book .. . a) The speed at the beginning of the interval is words per minute. (Simplify your answer.) urce Lib esource: tions