Answer:
58 miles/hour
Step-by-step explanation:
Given that the family Christmas gathering has been scheduled at 2:00 p.m.,
and Joshua left the house at 8:00 a.m.
So, the total time available in order to arrive on time to attend the Christmas gathering, t=6 hours
The total distance, Joshua has to travel, d= 348 miles.
As average speed= (total distance)/(total time)
So, the average speed of driving = 348/6=58 miles/hour
Hence, Joshua must drive at an average speed of 58 miles/hour in order to arrive on time.