Answer
(a) $-0.0167$, see explanations.
(b) World Wars I and II.
(c) $13.05\ min$, underestimated $0.3\ min$.
Work Step by Step
(a) Given $y=-0.0167x+46.45$, we can identify the slope as $m=-0.0167$ which represents the average rate of change (in min/year) using this linear model during 1912-2012. The slope is negative because the time decreases (new records) with year.
(b) Possibly due to the two World Wars (I and II) when the Olympic were cancelled.
(c) For year 2000, we have $y=-0.0167(2000)+46.45=13.05\ min$, The actual value was $13.35\ min$, thus the model underestimated the time by $|13.35-13.05|=0.3\ min$.
