The bacteria in an old piece of cheese is growing at a rate that can be modeled by y = 280 • 2^x. determine which number represents the growth rate.
a.) 0.5
b.) 1
c.) 2
d.)280

The answer is C.) 2

The general form of formula is
y = a • r^x
y - the total number of bacteria after x period of time
a - the initial number of bacteria
r - growth rate
x - period of time

Let's compare:
y =    a   • r^x
y = 280 • 2^x

Since r = 2, the growth rate is C.) 2