Final answer:
Sherman's rate of biking is 18.75 miles per hour.
Step-by-step explanation:
To find Sherman's rate in miles per hour, we need to convert the time from hours to minutes. Since there are 60 minutes in an hour, we can convert 1/3 hour to 20 minutes. Now, we can calculate the rate using the formula: rate = distance / time.
Substituting the values, we have: rate = 6 1/4 miles / 20 minutes.
To make calculations easier, we can convert the mixed number to an improper fraction: 6 1/4 = 25/4.
Then, we can divide the distance by the time: rate = (25/4) / 20 = 25 / (4 * 20) = 25 / 80 = 0.3125 miles per minute.
But we are looking for the rate in miles per hour, so we can multiply the rate by 60 (since there are 60 minutes in an hour) to convert it: rate = 0.3125 miles/minute * 60 minutes/hour = 18.75 miles per hour.