In January 2015 a scooter company sold 4000 cars. In July 2015they had sold a total of 7500 scooters. Assuming an exponential model for this growing...

In January 2015 a scooter company sold 4000 cars. In July 2015they had sold a total of 7500 scooters.

A.     Assuming an exponential model for this growing scoot sales. Find the growth constant K. Round the answer for K to 4 decimal places.

B.      B. Find the function N(t) which gives the scooter population after t months

Any guidance would be greatly appreciated.