Running around a circular track that is 200 meters in circumference, an observer used a stopwatch to record the runner's time at the end of each lap, obtaining the data in the following table:
Distance (m) Time (s)
200 120
400 172
600 226
800 281
1000 348
1200 422
What was the runner's average speed (rate) between 74 and 172 seconds? (Round your answer to two decimal places.)
What was the runner's average speed between 281 and 422 seconds? (Round your answer to two decimal places.)
Calculate the runner's speed for each lap. Is he slowing down, speeding up, or neither?