The number of barrels of Texas
crude oil produced per month
grew at an average rate of 221%
from June 2010 to February 2013,
The average number of barrels
of crude oil produced per month,
in thousands of barrels, can be
modeled by y= 1142(1 + 00221)
or y= 1142(1.0221)' where tis the
number of months since June 2010,

How do you know the
function isn't linear?