### Home > INT3 > Chapter 2 > Lesson 2.2.1 > Problem2-38

2-38.

The Gross National Product (GNP) of the United States in 1960 was about $2.19·10^{12}$ dollars. Suppose it increased at a rate of $3.17\%$ per year. Use this information to answer each of the questions below.

1. What was the predicted GNP in 1989?

Multiply the GNP in 1960 by $1.0317$ twenty-nine times.

$y=2.19·10^{12}(1.0317)^{29}$

The GNP in 1989 is about $5.41·10^{12}$ dollars.

2. Write an equation to model the GNP $t$ years after 1960.

Remember that the GNP increases by $3.17\%$ each year.

$y=2.19\left(10^{12}\right)(1.0317)^t$

3. What assumptions did you make in creating your model? How accurate do you think it is?

If you don’t know or you aren’t sure, try looking it up on the internet. Look for a graph. You could enter GNP USA into a search engine.