Explanation:
We can start by converting 4 hours and 45 minutes to decimal form, so that we can use it in our calculation.
4 hours and 45 minutes is equivalent to 4.75 hours, because there are 60 minutes in one hour, so 45 minutes is 45/60 = 0.75 hours.
Now, we can use the formula:
distance = speed x time
where speed is in miles per hour, and time is in hours.
Plugging in the given values, we get:
distance = 68 miles/hour x 4.75 hours
distance = 323 miles
Therefore, the car travels 323 miles in 4 hours and 45 minutes at an average speed of 68 miles per hour.