Question

The sales at a particular bookstore grew from $2104 million in 2000 to $3881 million in 2005. Find an exponential function to model the sales as a function of years since 2000. Give your answer using the form B = Boat.

Answer 1

The usual exponential growth equation is given by: 

y = C * e^kt,  where k greater than 0. 

t is the number of years, in this case (2005 - 2000), t = 5 years
C is a constant at x = 0
k is the growth constant

There will be two equations:

2104 million = C * e^k(0)

so, C = 2104 million, the other equation is:

3881 million = 2104 million * e^k(5)

solve for k:
k= 0.12245

The exponential growth equation is:

y = 2104 million * e^(0.12245*t)