Final answer:
Hillary's estimate of walking about 200 feet per minute is reasonable, as a simple calculation shows her speed to be 218 feet per minute.
Step-by-step explanation:
Yes, Hillary's estimate that she walked about 200 feet per minute is reasonable. To verify this, we can divide the total distance walked by the total time it took. This results in 654 feet divided by 3 minutes, which equals 218 feet per minute. Hillary's estimate rounds down slightly, but it is close enough to be considered a reasonable approximation of her walking speed.