### Home > A2C > Chapter 4 > Lesson 4.2.1 > Problem 4-73

The gross national product (GNP) was 1.665 · 10

^{12}dollars in 1960 and it increased at the rate of 3.17% per year until 1989. Use this information to answer each of the questions below. (The number 1.665 · 10^{12}is expressed in scientific notation. Written in standard notation, the number is 1,665,000,000,000.) Homework Help ✎What was the GNP in 1989?

Write an equation to represent the GNP

*t*years after 1960, assuming that the rate of growth remained constant.Do you think the rate of growth really remains constant? Explain.

*y* = 1.665 · 10^{12}(1.0317)^{29}

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

The GNP in 1989 is 4.116 · 10^{12} dollars.

Remember that the GNP increases by 3.17% each year.

*y* = 1.66(10^{12})(1.0317)^{t}

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.