Answer:
a. He used an incorrect time ratio converting hours to minutes.
d. He incorrectly concluded that she is not running fast enough.
Explanation:
Looking at the Coach's method of conversion when converting time, he assumed that an hour had 15 minutes instead of 60 minutes. He therefore did not use the correct time ratio to convert hours to minutes.
The coach's calculations yielded an answer of 34 ft/s. This is way faster than 8.8 ft/ s so his deduction that she was not running fast enough to beat her fastest time is incorrect because at that inhumane speed, she did.