Final answer:
The rate of walking per hour for the missionaries was 5.4 miles.
Step-by-step explanation:
To find the rate of walking per hour, we need to divide the total distance walked by the total time taken. In this case, the three missionaries walked 27 miles in 5 hours. To find their rate of walking per hour, we divide 27 miles by 5 hours.
27 miles / 5 hours = 5.4 miles/hour
Therefore, the missionaries walked at a rate of approximately 5.4 miles per hour to the nearest mile.