A student bought a smartwatch that tracks the number of steps she walks throughout the day. The table shows the number of steps recorded t minutes after 3:00 p.m.on the

first day she wore the watch. (a) Find the slopes of the secant lines corresponding to the given intervals of t. (b) Estimate the student's walking pace, in steps per minute, at 3:20 p.m. by averaging the slopes of two secant lines from part (a). (Round your answer to the nearest integer.)