The average age that a person has their first cell-phone has been decreasing
by approximately 10% each year since the year 2005. In the year 2005, a
person typically didn't get their first phone until the age of 20. The following
equation models the average age of getting their first cell-phone, y, as a
function of the number of years after 2005, x.
y = 20(0.9)*
Using this model, what is the predicted average age at which a person gets
their first cell-phone in the year 2020, rounded to the nearest tenth?
Answer =
years old