A car has the velocity of 2.35 after 4.67 it's velocity is 9.89 what is the average acceleration

Average acceleration = (change in speed) / (time for the change).

Change in speed = (ending speed) - (beginning speed)

= (9.89 miles/hour) - (2.35 yards/second) = 26,839.2 ft/hr

Acceleration = (26,839.2 ft/hr) / (4.67 days) = 2,873.58 inch/hour²