The cost for operating a commercial truck is knv (1/2) where k is a constant of proportionality, v is velocity in miles per hour, and n is the trip length in miles. It is estimated that at 89 mph, the average cost of operation of $5.3 per mile. The truck owner wants to minimize the cost of operation, to do this he requires to balance the operating cost against the cost of delays and unscheduled maintenance, which is assumed to be $10.35 per hour. What is the optimal velocity in miles per hour required to minimize the total costs? (Provide answer with one decimal place precision).