Answer:
66622.653 mi/hr
Step-by-step explanation:
The average speed at which the Earth rotates around the Sun = 29.783 km/s
Also, The conversion of km to miles is shown below:
1 km = 0.621371 miles
The conversion of s to hr is shown below:
1 s = 1 / 3600 hr
So,

Thus,
The average speed at which the Earth rotates around the Sun in miles per hour = 66622.653 mi/hr